How? Most people this rich have next to nothing in their bank accounts. The ridiculous numbers you see are not bank account balances or sports cars and yachts. Its primarily shares of the companies they manage. E.g. if you tax them conventionally, you force them to close the factories and everyone becomes poorer. If you just confiscate the company (shares), now the government owns companies, and we saw how that goes plenty of times: USSR, North Korea, Cuba, … Or you give the shares to people, but the company would still need to be managed by someone who no longer has a proportional incentive to make it succeed, causing the same result as if it was government run.