Does money corrupt, or is money attractive to questionable people?
I was gonna include a third option about how money is easier to achieve without considering the morality of your actions but that's not really a philosophy as much as it is an objective fact.
I would say "meaningful". Billionaires can have a very noticeable effect with their philanthropy, while making essentially no sacrifice on their part. The Gates Foundation does very noticeable good, but Bill Gates isn't giving of himself very much.
OPs point stands, though, because we could still do that without Gates, and for every Gates there's a Musk that does evil and a ton of Arnaults and Bezos's that just spend it on whatever.