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.