The rub here is the definition of rich.
Sort of, but it goes back to the overwhelming size of government budgets. In the US for example, even if all of the assets of the wealthiest individuals could be converted 1:1 into cash (it can’t) and the government took 100% of it, congratulations, we’ve fully funded the government for perhaps one year. There’s nowhere to go at that point except to revise the definition of “rich.”
It started off at 1.2% about 2 decades ago (legislated as a 30% rate on a deemed 4% return), but has increased to 2.1% last year (36% rate on deemed 5.88% return), and in the current government budget proposal is set to increase to 2.8% next year (36% rate on deemed 7.78% return).