On a $6 billion net worth (like Cuban's), his yearly wealth tax would be around $319 million, which is roughly the amount his net worth went up over the last year. So he likely wouldn't get any poorer (at least not by much) but he wouldn't really get any richer unless he had a really good year.
Warren Buffet has openly shared his tax contributions without whining🙄
Buffet is from an older generation of businessmen who didn't see "tax" as such a dirty word but knew that higher tax rates were the price they paid to keep enjoying their positions and wealth. Spreading the wealth around is also a way to keep the peasants in line and stimulate more economic growth.
On an average year these guys are making 10-15%, and mostly more given the stock market performance recently.
I based my assessment (Cuban's wealth wouldn't decrease but probably stay the same) on the change in his net worth from 2023-2024. Those estimates are probably low and were from the same year he launched his mail-order prescription company, which likely reduced his gains.
As you pointed out, a wealth tax like Warren's likely wouldn't reduce his wealth, just make it grow slower. Which to people in Cuban's tax bracket is just as bad as robbing them and then leaving them to die in a ditch.
Yuuuup
I just can't imagine having that much money and then not wanting to use it to transform the world in some positive way. Any of them could use their business experience to create worker-oriented systems that were self perpetuating, profitable, and turned their founders into cultural gods.
But no, they just want number go up