I spent half my 20s (in various spurts) living off savings trying to do solo lifestyle business entrepreneurship but mostly just building for a non-existent audience and none of those stretches would have been registered as any form of 'employment', as I didn't bother to register any sort of business or have any income to report.

If you have a good job and live very frugally in a cheap COL area with roommates, cooking your own food, and no one else to provide for, it's achievable to only work half the time and live off savings the other half.

Wonder if there's a generation of men who have stints of trying to make an app, or learn coding, or make it big as a YouTuber or soundcloud rapper, etc. who don't show up in employment statistics.

It could be "savings" for some of them. I know guys (engineers) who work for a couple years, save up a bunch of money, they drop out of the work force for a while.

On the opposite side of the spectrum, I also have a friend with a "fake" job at a family business. They have an income, but don't actually work for it.

Being from EU-context, I'd like anecdata to say either way if my take makes any sense:

Shared flats/houses with no official subletting. Basically you have a friend (of a friend) who can barely but legally afford a place for themselves that are happy to give you a room/couch/corner for pitching in some money.

Loans, spouses, parents, disability, FB marketplace/craigslist, selling drugs, other side hustles that aren't reported

I make $200k and spend 30 a year. Obviously an outlier but not planning on working much longer.

Either living with parents or are taking your tax dollars in the form of welfare.

You need to pay rent to pitch a tent on the sidewalk in a West Coast city?