Assuming you never had to spend any of that money to live on.

Yes, assuming you are not paying taxes and don't have to spend it 😂 And obviously, if you are at 500M, maybe you have better ways to get richer.

If you are at $10 million savings, prudent investment should give you $500k a year, and only a really stupid person couldn't manage on such income.

$10 millions is unreachable in a lifetime though

Fortunes above $10 million should be heavily taxed for that very reason, because reaching this level through work (which is taxed) is rarely possible, if ever.

Obviously it's not possible by normal (working) means. It's just not possible. 100$/h 100h/week would be 20 years, without taxes or cost of life. And not everybody makes 100$/h or do 100h/week.

Money like that is never made through wages (unless you're a football player or Taylor Swift, and they don't get paid by the hour). When I sold my first house, I made about 10 years income in one lump. The property tax valuation on this place has gone up over $1 million since I bought it.