First up, the "starving artist" cliché isn't one because of those artist who got really really rich. It's a cliché because of all the very poor artists that were starving.
Secondly, survivor bias. Don't focus on the few artists who escaped the clutches of starvation to frame the group as a whole. Especially in case the calling may be abandoned in order to not starve.
How many "starry night"s could we have had if no one ever needed to Weeley about food, shelter, or safety?
We've got one, from someone who worked about all of those at various points in his life.
Probably much fewer. Part of the allure of starry night is the backstory and toil involved - not the same as some fat complacent well off guy painting pretty pictures in a nice house.
And the 20th century was quite full of rich artists making it, too.
In areas like startups, where family connections, early education, family environment, and fallbacks, matter, yes.
But the 20th century was full of people from poor backgrounds (includings immigrants arriving with 0 dollars) making it in e.g. arts. So much so, that the "starving artist" is a cliche.
(And of course, starting and succesfully running regular businesses - the 99% of businesses kind, from grocery stores and restaurants to design studios and software houses, not the 0.0001% that is VC-backed startups sold for b/millions).