If the tax rate is 95%, a company would have to pay someone a $21 million dollar salary to pay that person $2m. I suspect that no company would do such a thing, as it's just throwing money away.
5% of a very large number is still a large number. Very few people are going to say "don't give me that extra $20 million because the government will take $19 million." $1 million is still a lot of money.
And of course, there are lots of deductions. You could give that $20 million to a charity and the government would get none of it. You wouldn't get any either, but you could certainly get a lot of indirect value out of giving away $20M.
What company is going to pay that? It's just silly. If you felt that a CEO/athlete/whatever was worth $30m a year, you'd have to pay that person $581 million dollars. They'd find some other way, that money wouldn't go to the government.
And of course, there are lots of deductions. You could give that $20 million to a charity and the government would get none of it. You wouldn't get any either, but you could certainly get a lot of indirect value out of giving away $20M.