100% wealth tax rate past e.g. $999M -- capping wealth like a Zelda wallet -- would address a certain number of issues around the many externalities of unbounded, bottomless greed.
Mind you, I don't think that's ever happening, considering that one such issue is there's currently nothing to keep a dishonest actor who ended up beyond that threshold from spending mountains of cash (still a small fraction of the total there) toward convincing those susceptible to such that a system which permits such dishonest actors is good akshyually.
Not sure why you're being downvoted. This is a very reasonable proposal. Once you're beyond a certain level of rich, you should be constrained by whether the people around you consent to your behavior, not how much money you have.