I'd
like an actual policy that prevents people from accumulating (or at the very least, leveraging) $1b in wealth. But I won't let the complexity of said policy affect my opinion about the ethics of accumulating so much wealth. Those are completely independent topics.
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.