This is silly. Bill Gates thinks his taxes should be higher, because he thinks all people earning money in the way he does should pay higher taxes. If he wrote a check to double his own personal tax payment it wouldn't make a dent in the US budget. But if you doubled the taxes every billionaire pays, it would make a huge dent.

So he's saying, his class of wealth should pay more. If it's just him who does it, it doesn't solve the government's problems, and he's better off spending the money himself directly on the things he cares about. But if everyone at his scale paid more, that _would_ help.