Given we have a poverty line, beneath which we (as a global society) have agreed no-one should fall (even if in actuality we have not always managed to ensure that), perhaps we also need an extreme wealth line above which we would agree that accumulated wealth is too much for one family or individual?
Dhananjayan Sriskandarajah's proposal makes sense but might be difficult to deliver politically, but equally, things seem impossible until they are not!
https://www.theguardian.com/commentisfree/2025/may/17/sunday-times-rich-list-extreme-wealth-damage