I don't know. Somebody needs to make those huge decisions, and it is not always clear if that should be by democratic means (here is to you, Trump and Brexit).
But incidentally, someone's ability to make a lot of money (or worse: inherit it) doesn't imply that they have any preferential ability to spend it in a way that benefits society. And when someone has the unchecked power to spend massive sums of money on themselves in ridiculous and frivolous ways, it's pretty clear that they have too much power. Because whoever should be making those decisions should certainly not be doing that.
Bill Gates rented a yacht for $5M/week. How is this not a clear waste? How much suffering could have been avoided at that cost? At least put it in some kind of public trust where such behavior can be properly considered corruption.
Those $5M don't just get lit on fire. They transfer to some other set of people who can then decide what to do with it, and then onto some other set of people. Maybe the yacht's owner donates all proceeds to feed starving children.
Not trying to argue that luxury goods are pure evil, but there is a degree of selfishness in having luxury goods for yourself when there are people who lack the basics.
Only saying it would be /even better/ if the people currently spending fortunes on yachts spent the money building libraries and the like instead.