Who is actually making max contributions? $19k per year is out of reach for most. If someone makes the max 401k and IRA contributions over a 35 year career, they would be set.
I suspect all of the exempt employees of Meta, Apple, Google, Microsoft, Intel, and pretty much the ones in any of the other fortune 100 companies.
There is a funny thing though, you can have "too much" in your 401k/IRA :-). When you hit 72 you have to withdraw 10% annually and that amount can put you into the top tax bracket if you've been saving your whole career and have more than a million bucks in there.
Required minimum distributions start at about 5% (not 10%) at age 72, and increase with age. But your general point stands. RMDs will add to one's tax bill, by regular tax brackets and having up to 85% of Social Security benefits taxed too.
They’re would be set assuming continued US stock market returns, which will “probably” continue indefinitely so long as we are a country, but it’s not guaranteed. If I recall correctly, maxing out 401k for 30 years doesn’t even get you $1M on principal. 30 years from now even $2M is probably not enough to comfortably retire on.
Then if you need any nursing care it’s $100k+ per year.