Well, assumed you were talking about sums < $1B. I can think of useful (starting businesses, research/engineering projects) things to do with up to $1B or so.
Now, suppose we wanted to cap individuals at say $2B. How would this actually work? That's not cash that's lying around. Almost all of Buffett's wealth is in equity of Berkshire Hathaway. He can't sell that without also losing ownership of BRK. Is BRK worth as much without Buffett and/or the people he's explicitly groomed?
Billionaires are billionaires not because of their income, but because of the assets that they control.
Now, suppose we wanted to cap individuals at say $2B. How would this actually work? That's not cash that's lying around. Almost all of Buffett's wealth is in equity of Berkshire Hathaway. He can't sell that without also losing ownership of BRK. Is BRK worth as much without Buffett and/or the people he's explicitly groomed?
Billionaires are billionaires not because of their income, but because of the assets that they control.