I think billionaires would typically rather get eaten than lose their gains. Hence the willingness to risk human extinction over number not go up so much.
Why do that? Too quick and easy. Exile them to a tiny desert island where any supplies they are given are proportional to how much they paid their lowest paid employee. To earn this they must do a mind numbing repetetive task while random hidden speakers and sprinklers go off, disrupting their waking and sleeping hours.
As much as I can appreciate a good revenge fantasy, as a society we should refrain from driving people to suffer, including as a form of retributive justice.
One of the things that I thought of to help with this problem is, like, what if we figured out how much it costs to meet like all the basics in life - a house (not a rental!), food, soda, internet, heat/hot water - all that stuff. Then add some more, so that people could do nice stuff and enjoy their lives, save for retirement, go on vacations, etc.
Then - now here's the crazy part - we make a law requiring that everyone in the country needs to be paid at least that much money. It would be like a "Floor Wage," or, like, a "Minimum Salary."
If the increase in the cost of doing business didn't eliminate billionaires altogether, I bet people would at least stop giving a shit about billionaires and their gold piles because the rest of us aren't living in debt while they build yachts for their yachts.