Wealth inquality (up to a point, of course) is, in general, actually a good thing. The more concentrated wealth is, the more easily and more cheaply it can leveraged to affect change. A good example might be the Gates Foundation. Through Bill Gates’ concentration of wealth, he can allocate money to help the world with very little friction and overhead

Other examples include VC or hedge funds. While they don’t own the money themselves (they merely aggregate and invest it on the behalf of others), the reason this happens is because it’s much more profitable and efficient to invest one large pot of cash vs many small pots of cash.

PS: If someone wants to bring up that index funds are better, it’s still the same principle at work. The expense ratio of a S&P 500 index fund are much smaller than what most individuals could manage themselves.