I'm not sure everyone is clear on the meaning of the 4% rule. The objectives are simplicity and very high confidence that one will not run out of money within 30 years.
Conditions will surely change -- but we don't know when or in which direction -- adjust as necessary
Simplicity: just stay the course, KISS, come hell or high water. No adjustments necessary.
Gives example of how a target date fund
Simplicity: Target date funds follow glide paths. The 4% rule hews to a fixed allocation.
How can you straight line the 4% without taking these inputs into consideration.
Starting in 1926, a 4% (inflation adjusted) withdrawal regimen from a 50/50 portfolio has never depleted assets in under 30 years. That includes starting in years like 1929, 1973, 1981, etc. The rule already incorporates objective risk, assuming past is prologue.
That's not to say that people are subjectively able to handle sequence of return risk. And some people may want to plan for more than 30 years, either because they expect a longer life in retirement or their end target value is not simply "better than $0". They want to leave a legacy. And stuff happens; people may not be able to keep to a 4% budget.
ISTM the biggest risk in the 4% rule is being left with too much money. Planning for worst case without adjustments is necessarily conservative and likely to "fail" on the upside (not spending enough). But by definition any strategy that includes making adjustments is not the simplest possible.
For those who want to limit the risk of underspending, are willing to accept some risk of having less to spend in some years than they might otherwise like, and can manage more complex strategies (or are willing to hire someone else to do that), @Observant1 cited a good discussion of a couple of such strategies.
Finally, using cash is very likely to fail. Over the past 96 years (1928-2023 inclusive), 3 mo. T-bill real returns have averaged 0.32%. (See cell T120 here.) Take 4%/year off of that and you're losing more than 3.5% annually. Even without compounding the loss, you'll run out of money in under 30 years.

All I thought I did in the post you quoted was attempt to respond to the OP about our market participation level and briefly specify how. That ain't bragging in my books but YMMV.

@stillers, you may not realize it, but you do pretty much brag in every post you make. A lot in common with your buddy, FD. Not saying your ideas aren't good ones and they are often timely, but you do often toot your own horn.
Just in this thread alone:
I tried earlier this year on this forum to stir others to participate
I've promoted the fund for YEARS
I projected (several times)
I could list our OEFs with their YTD TRs and/or re-visit my ST trades from early this year on NVDA and GOOGL

FWIW, I tried earlier this year on this forum to stir others to participate in Semis and the MAG7, but with little success. Much better success elsewhere as many on another forum jumped on board the FSELX train early this year.

"He who tooteth not his own horn, the same shall not be tooted."

I think you got the wrong guy. It's my brother who has the PhD in English!
Me? I nearly flunked English Lit, so sorry man, I have no idea what that means.
But...WAG, if it attempts to suggest I'm bragging and something bad will ultimately happen to me for doing so, I'm gonna go ahead and respectfully disagree.
FWIW, we've owned FSELX since near its inception. I've promoted the fund for YEARS and nothing real bad has happened to me (yet?) for doing so.
As well, I projected (several times) Semis would Rock the Casbah at BOY 2024. I tried here and elsewhere to help others jump onboard both the Semis and MAG7 trains. Took a lot of abuse in doing so, especially on the MAG7 posts. But again, nothing real bad (yet?).
All I thought I did in the post you quoted was attempt to respond to the OP about our market participation level and briefly specify how. That ain't bragging in my books but YMMV.
If you want bragging, maybe I could list our OEFs with their YTD TRs and/or re-visit my ST trades from early this year on NVDA and GOOGL?
But I'll never know unless you drop the old English stuff and just say what you mean.

@stillers I'm with you on FSELX. It was the first purchase in my wife's Roth IRA back in 1998. Bought some more two years later. Needless to say, she's happy with the 25-year tax-free growth.
It's also my biggest holding in my Rollover IRA.
I have some ASML in my Roth IRA.
Sometimes it's a wild ride, but I'm patient. Aggressively so, for an octogenarian.
When our teenage grandson became interested in investing a couple of years ago, I insisted he buy SMH first.
David

IMO, the most compelling CP CD rates are at 5 years. This is a moment in time that will pass far quicker than many here think. Not sure what is compelling about 1-12 mo rates when Prime MMkt funds are paying just about the same and provide full flexibility for that bucket.

Sorry being late to this discussion. Our oversea exposure is about 7-8%, with mostly actively managed funds and ETFs. In taxable account, VEA and DIVI are the only one we use and they are tax efficient.
1. For large cap developed market, ARTKX and FMIJX are the main vehicles.
2. Lately CCGO was added to gain exposure to the “growth” stocks in Europe as BF mentioned the “Fantastic Five”. Capital fund does a good job so far managed the downside risk than that of Vanguard Int’l growth (we moved on when Ian Anderson retired).
3. For EM exposure, we have 2% and it is getting smaller; largely invested in Seafarer funds with Andrew Foster and his teams.
4. The only stake on int’l small caps we have is Seafarer EM Value.
5. We continue to seek actively managed funds and ETFs with lower ER; preferable less than 1%.
6. Back in the 80-90’s when US currency was less dominated to other currencies, many international funds often out-performed the US counter-parts. This has changed in the last 10 years as it reflects in our lowered exposure.
7. In our 529 plan, Vanguard Total International stock index fund is used as part of the portfolio but we have limited choice there. Preferably, the Total Stock Market index would be better.

IF one wants to follow Bengen's original paper, then one should (I think) be using large cap domestic stocks and intermediate term Treasuries. (He is clear about intermediate term treasuries but says only "large cap" stocks.)
These days, many allocation funds invest a significant fraction of their equity sleeve abroad. IMHO that's not a bad thing, but it is different. A related "problem" is that allocation funds often invest some money into small cap stocks. While this is different from Bengen's original work, it could be an improvement:

Bill Bengen ...has increased the withdrawal rate he uses on his own retirement portfolio to 4.7%, largely because of the upside he’s gained by adding small and microcap asset classes to his portfolio, he told the Bogleheads Live podcast this week. [Dec 2022]

https://www.fa-mag.com/news/creator-of-4--rule-says-new-withdrawal-target-is-4-7-71026.html
That page goes on to say that these days, Bengen says that "the optimum stock allocation that allows the highest withdrawal rate over the long term is between 55% and 60% over the long term."
That suggests that you might look at 60/40 funds, of which there are many. As to what Bengen himself is doing, rather than using his stated static allocation "he uses a third-party service that recommends changes to his asset allocation based on perceived changes in the marketplace."
In short, consider looking at funds closer to 60/40. VBIAX (0.07% ER) is a good starting point if ER is paramount, or VSMGX (0.12% ER) to add foreign exposure.
FWIW, here's a portfolio visualizer comparison of three 60/40 funds: AOR, VSMGX, and VBIAX. over roughly ten years (PV limitation). Starts with $10K, $400 (4%) annual withdrawal (inflation adjusted).

"Isn't Intl investing really a currency play on a weaker dollar...which might be in our near future, no?"
Foreign currency weakness / strength against the dollar affects returns but there is more to the story.
S&P 500 companies derive a significant portion of their revenue overseas.
However, some excellent companies are domiciled outside of America.
I would like to own these companies.
Foreign stocks may provide diversification during longer periods
where S&P 500 performance is dismal (e.g., 2000 - 2009).
Of course, diversification works both ways.
Foreign stocks have lagged U.S. stocks for approximately 15 years.
This is an unusually long period and U.S. / foreign stock outperformance tends to run in cycles.

William Bengen published Conserving Client Portfolios During Retirement, Part III
in the Dec. 1997 Journal of Financial Planning. His recommended range for stock allocation
was between 50% and 75% for a 65 year-old investor.
"Because withdrawal rates within the recommended range of stocks are essentially equal,
they are not very useful in selecting stock allocation.
For another view of the matter, consider Chart 10, which depicts the nominal wealth built up
in a portfolio after 30 years, for a retiree who began withdrawing four percent the first year.
The two stock allocations displayed, 50 percent and 75 percent, represent the extreme ends
of the 'recommended range' for this investor at age-65 retirement."
PDF1
Edit/Add: Bengen published Conserving Client Portfolios During Retirement, Part IV
in the May 2001 Journal of Financial Planning. Two alternative withdrawal strategies are explored.
PDF2

I read with great interest Devesh Shah thoughts this morning and reasoning on helping to take the international allocation on the endowment he serves on down substantially.
The question I have for him with zero criticism is I have read and watched Nobel prize winners like William Sharpe and Eugene Fama and Fama’s frequent collaboration Ken French suggest that there is very little signal in observations five , ten, or even twenty years out.
Shah who is clearly a very smart person must know that.
In order to move as sharply away from where the global portfolio clears or reaches equilibrium he is in fact making a big tactical bet.
If we enter a period like 2000-2010 where essentially the S&P had zero returns ( not impossible given the elevated valuation of US stocks) the “bet” the board made goes against the idea of being market agnostic.
I’m curious if they aren’t succumbing to recency bias even though the recency has persisted for a very long time?

Using Savings Bonds for education has many restrictions.
https://treasurydirect.gov/savings-bonds/tax-information-ee-i-bonds/using-bonds-for-higher-education/
We bought some DECADES ago, and when these "new" rules came along, our bonds didn't qualify for one reason or another. By that time, we had stopped buying them, but just held them. Now, all have matured naturally (30 years) and we are Savings Bond free except for the I-Bonds we bought in 2021-22 during the mad rush when inflation was very high.
But the rules for using Savings Bonds for education could certainly be simplified.

Oh there's always the piker mania and get-rich-quick schemes every few years - remember the daytrading rage during Dot Com? The housing bubble, another one. And so forth.
I just find it amusing in this case -- but I don't see the USG or Fed backstopping retail investors who lost $$$ on meme stocks based on whatever an influencer and/or the majority of a subreddit is buying at any given time. (I'm sure it's perfectly LEGAL for him to discuss his investments, though.)
BTW 'Dumb Money' was a recent movie about the guy behind DFV and the GameStop circus.

I have some 8% international in the actively managed portfolio. CGXU and OSEA for international LC, CGGO and GQPRX for global and BISAX for international SC.
I switched to BISAX after HIISX disappointed me in the last two years. Both of those funds had terrible performance in 2022, for that matter. DIVI is a good choice, but its benchmark changed not long ago, making long-term comparison difficult.

”Let's ask the obvious easy question: if you held just the SP500 for your stock portion (based on Bogle+Buffet) have you done well YTD + in the last 3-5-10-15 years?”

The S&P 500 lost approximately

56.8% of its value between October 2007 and March 2009, according to the historical performance data. This significant decline was a result of the 2008 financial crisis and the Great Recession. (Credit: Brave Search AI summarizer)
Hey big guy - Every dollar you held in your S&P 500 index fund in October 2007 was worth 43 cents 16 months later. Sound like fun?

And...how much did the SP500 ended at after 15 years = 6/1/2008?
418% which includes the 50% loss that happened as you noted above, but wait, since 2010 I have been posting why you should invest in US LC tilting growth, SPY has been an easy choice but you could also invest some in QQQ. If you invested in QQQ you ended at 934% (https://schrts.co/zTCFZQSB)

”Let's ask the obvious easy question: if you held just the SP500 for your stock portion (based on Bogle+Buffet) have you done well YTD + in the last 3-5-10-15 years?”

The S&P 500 lost approximately 56.8% of its value between October 2007 and March 2009, according to the historical performance data. This significant decline was a result of the 2008 financial crisis and the Great Recession. (Credit: Brave Search AI summarizer)
Hey big guy - Every dollar you held in your S&P 500 index fund in October 2007 was worth 43 cents 16 months later. Sound like fun?

Based on (https://stockcharts.com/freecharts/sectorsummary.html) ...
Everything was up, but technology lagged, the less you own tech, the better your portfolio made for one day.
Rates were down = most bond funds made money.
Let's ask the obvious easy question: if you held just the SP500 for your stock portion (based on Bogle+Buffet) have you done well YTD + in the last 3-5-10-15 years?

I am sort of going the other way. As my CDs mature, I am redeeming them. The last one will mature in about 2 months. Putting the cash in our MM fund for right now. It is paying a fraction over 5.25%, but plan to later go with a I-T Bond Fund.
I do like CDs, but always having to search for the best rate to reinvest as they mature is something my wife would not want to do when I am gone. No, that is not true, it is something she would not do, so I'm going with I-T Bonds with the dividends reinvested.
I am 86, she 85, so we don't think in long terms any more.

hondo, I wish you nothing but the best, and you know what is best for you and your wife.
A big part of my decision to use CDs, besides their attractive yields recently, is my wife understands CDs. We use to invest in CDs extensively about 20 years ago, but then the market crashed, banks started closing, and CD rates started dropping like a rock. During that period, my wife became the elderly caretaker of her mother, and worked closely with me to select CDs paying in the 5% range--they were all over the place at local banks and she use to go with me to various banks to buy a CD. My wife fully understands the basics of Bank CDs, interest rates, redemption fees, reinvesting dividends or capturing dividends, etc.
When CDs started to resurface as a viable investing option about 2 years ago, she and I discussed what we should do with our Schwab Brokerage Accounts (her IRA, my IRA, and a Joint Taxable Account). We had cashed out of the market, and had investing options to talk about. She was very excited about the option of using the CDs available at Schwab, and she has learned the differences between a Bank CD and a Brokerage CD. Because of my wife's understanding of CDs, her comfort with CDs, and my desire to feel good about my wife knowing how to work with the Schwab Brokerage office close to where we live, I continue to such all of the returns out of CDs, as long as I can. My wife and I talk about every CD I purchase and for the first time in many many years, my wife is involved again in our investing decisions--that is of huge importance to me!

We have about 5% international. Most of that ( 60%) is in individual stocks run by the manager we use for about 20% of our total portfolios.
He has done a super job in the last two years with just about 6 foreign stocks. They are up 75%, a lot better than his domestic picks.
We also have about 2% in Emerging markets
We own MOWNX CVISX EWJV BISAX SIGIX GQGPX and KGIIX and a smattering of some Chinese ETFs

Initiated a new stake in GPQFX today. Adding to LCR (thanks @David Snowball).
Bought 2yr Treasury at auction on Tuesday. Next Monday I will buy more 1 yr Treasury to extend the duration on the treasury ladder.
Correction: June 6th is when one year treasury will be announced. So it the the following Monday, June 11th when the purchase takes place.
@Derf, For now 2 years T notes is the longest I like the ladder to be. But I won’t say never as I see other managers run a barbell ladder of treasuries. This year my investment grade bonds (mostly short to intermediate duration) have not done well. Ironically short term junk bonds carry the bulk of advancement. Cash cannot yield over 5% for long. So longer treasuries make perfect sense for now as it did well when the Fed hikes rate aggressively.

I share your enthusiasm, but my CD ladders extend out 5 years. I also include Treasuries in my ladders for shorter term holdings. CD yields have been on of the bright spots in the inflation dilemma.