If one person controls all the money in the world, would you consider that to be harmful to society?
If so, to what degree would that money/wealth need to be shared for that harm to subside to acceptable levels?
Probably not since the money would be worthless: why would anyone want to use this money?
In practice it would have collapsed before that point, but for basically the same reason. None of the capital is where it needs to be to be useful. This is why you need stuff like progressive taxes, public works projects, and social programs on top of capitalism, to pull money out of the top and re-inject it at the bottom lest the system get too top heavy.
The richest today are first generation - Gates, Bezos, Buffet, Musk, Case, etc.
Finding a gold nugget takes nothing away from anyone else. Wealth is not a fixed pie at all - wealth can be created, which is what free markets do.