… about expenses than savings.

Some folks can line on $3000/mo. Others spend more than $10k.

Suze might disagree. Her number went way up. I got lucky and retired early and waited til 65 for SSI. I don't have a lavish lifestyle. Saw too many not make it to retirement or become physically unable to enjoy it.

Is that cash? Net worth? How much SS? Etc.

It’s a general sentiment number.

On it’s own, that’ll safely produce about $60k imcome. Combined with social security, that’d produce from $80k-$100k+ pretax income, but lots of variables. And where you live and what you’re personal finance situation is makes a huge difference as well.

If a person with X-amount in a retirement account could live more comfortably in one state by just barely make by in another. I live comfortably in California but if I move to somewhere like Alabama or Louisiana I could probably live very well. But the problem with that is it isn't California. I choose to live in California because it has more to offer me than any other state.

If you own your home, you need less money, and the value of the home may well be less than the amount of money you would need to cover a mortgage for your expected lifetime. Then there's your age and health; if you're a diabetic you will need more money no matter how old you are. This "magic number" is probably just an estimate; the actual amount needed depends on your life.

At the downhill side of my sixties with a disabled spouse, a stepdaughter who's still failing to launch in her mid-30's, and two grandkids to raise, I expect to still be working to my mid-70's and maybe I'll hit 3/4 that number.
What really frosts me is the amount of influencer types on Social Media slyly telling the 20- and 30-somethings to just go ahead and live that excessive lifestyle you want right now when you're young because you just aren't going be able to afford those pleasures when you're a sorry old fart.
Live Fast, Party Hard, Die Young, and make sure the Corporations and Oligarchs get your money instead of saving to help you continue to survive when you can't or don't want to work anymore.

And my retirement has been super comfortable. I'm not in a super high cost of living area, but's it's not super low either. One advantage is Pennsylvania is one of only a handful of states that doesn't impose any state income taxes on Pension income.