Im 54 and been pounding Index funds since i got out of Texas. I didnt start being able to save money until I was 25, so figure appx 30 years of Index buying and holding. Almost entirely S&P 500, with the exception of 10% of the nest egg in cash (probably more than what is recommended). The strategy has served me well; without going in to too much detail, we should be fine. Buy and hold, dollar cost averaging, only time I sold was right after 9/11 and I was late to sell. Got it all back of course. Fortunately my company has a defined pension...that plus SS and savings and wife is realtor (she'll do that forever).... trying to go another 7 years before heading to the house.
I think the Boglehead strategy is not sexy and wont win the dinner conversation, but i come from the millionaire next door ethos where its best to sit back and let others discuss the next big stock pick and bide my time.
Full disclosure, I will say i have one IRA from my wife's previous employer where i own microsoft, Meta, apple , amazon and AMC (got caught up in the meme options mania), plus an inherited IRA with Vanguard in their inflation protected bond fund tied to 10 yr.... been a dog lately but with the 10yr under 4, it should start a price increase trend. Other than that, im all S&P.
Good luck!