Just because they weren’t born into the owner class (or “capital class”) doesn’t mean they didn’t work their way into it. That’s kind of the American dream.
Further having 100m at 40 doesn’t suddenly bring the kind of social connections that going to the right schools and the right parties would. At the extremes, the average lottery winner is surrounded by people asking for help, the average Fortune 500 CEO’s social circle aren’t. So if they suddenly fall on hard times the lottery winner is stuck but that CEO may very well claw their way back.
It’s still possible for poor people to succeed and 3rd+ generation wealth to fail, but the odds are wildly different.