Finding those people is harder than the Yacht idiots, but that's why we have watchdogs for public charities and can make laws regulating what people can do with a charity.
If people are making investments not as part of a public charity, we have journalists to hopefully keep some high level accountability, but yeah youn can do bad stuff with money in a lot of ways, go figure.
Even people doing lots of good can still be seen on a spectrum, I love a lot of the work Bill Gates is doing around the world, but I think he worked really hard to fight FOSS, and I think the world is worse off in some ways for it.
I'm saying buying crazy expensive luxury goods is never a good thing, it's just a waste of resources to prop up someone's shallow ego.