The size of taxes, of course, is impressive. However, it should be borne in mind that with small profits and tax deductions will be small. A little more than half of the profits are taken as taxes only if the profit is more than 367,000 dollars. I do not even know who can have such a big profit.
I think you shouldn't underestimate the amount of cryptocurrency millionaires that are actively trading. So for them it's easier to net $367,000 in profits annually since their initial investment capacity is a lot bigger. Of course this will target the people who are already rich but u think 55% is a little too much.