I think it’s self evident that very rich people have more capacity for both good and bad, as they have more power in a capitalist society. To debate further there is a debate about capitalism, and whilst I’d like to see more social democracy and less laissez faire, going beyond capitalism is not something I want to jump into…
So I think ideally you’d like to see billionaires give up their wealth voluntarily, right? That seems internally consistent.
I think your last point is a good one, particularly a good response to those on the right who are always against progressive taxation: the cash should not be the only or perhaps even primary incentive. At least for entrepreneurship.
One issue with saying “900m enough” etc. is that often billionaires (or rich folk) are really just rich on paper. If your company is private it’s not necessarily easy to liquidate, for example. And maybe sometimes you want people to “own” lots of money in the sense that they need to steward it (maybe you want them to be an Angel investor, for example).
I guess I took you away a bit from “unethical” to “how do we solve it?” And it is still valuable to have ethics that cannot be enforced, because you want to be ethical yourself and be able to advise others.
There are logistical issues with illiquid assets. Everybody knows this. This is not, in my opinion, an interesting concern.
One way to help solve it is to call billionaires shitheads whenever possible.