The reason why we are seeing pushes to adopt capital gains tax right now is because Bernie Sanders, AOC, et. al. want to "Tax the Billionaires." This is obviously a popular slogan because people think "who the hell needs 1 billion dollars?" But it's not like billionaires literally have 1 billion dollars just sitting in their bank accounts not doing anything. In reality, billionaires are billionaires because they make their money work for them through various investments. Capital gains tax is not "taking some poor billionaire's leftover yacht money," it's a tax on _the businesses they own_. Although capital gains tax disincentives the growth of business (which is a bad thing because we want businesses to grow,) it's marketed as a "tax on fat-cat bastard billionaires."