[uoaei]

This conflates "self-made" with "started with nothing". In some ways they align but they're not useful as synonyms.

The major difference between inheriting money and attracting investors is that you need to be more convincing for the latter to get the money on offer. The investor to whom you are otherwise a stranger might want to put some contract together to make sure they see a slice of the pie if you're successful (big if!), but if you fail they don't demand their money back.

But how can you call it "self-made" if you're using someone else's money? It doesn't matter which pocket it comes from, at some point very early in the process you are dependent on the pocketbooks of others.

[tooop]

You literally just described effort - doing everything possible to attract investors.

[uoaei]

Effort is effort -- I'm not saying billionaires did nothing to achieve their wealth. I'm saying that mythologizing them according to some sort of reverse-anachronistic fetish of rugged individualism/pioneering/entrepreneurship is fallacious. Effort to attract investors is a key to opening doors but don't pretend that the people who have the money you're asking for didn't do you a massive favor.