Most people don’t have enough capital gains to tax. If they do have capital gains it’s either in there house and unrealized or in a retirement account and deferred. Raising the capital gains tax almost exclusively targets the wealthy, not necessarily billionaires but still top quintile.

Raising this rate could discourage investing.

What else are people going to do with there money then? Keep it in cash and lose even more of it to inflation then you would with the tax?