The problem is how do you tax wealth that is mostly in the form of investments? How do you tell Bezos he has to dump 1% of his controlling interest in Amazon every year to pay his tax bill?
He did it to buy the world's biggest yatch, and a space program
Well it is like that because they're trying to make it harder to avoid paying the taxes. But obviously richer folks can pay for smart people who know the system very well and actually avoid all the system using loopholes.