Why isn't this applied to income taxes first? Does the government deserve a percentage with no cap of whatever you make? Your government services don't get better for you the more you pay.
You should look at it the other way, where ANY income or income equivalent, of any kind, should be taxed like income.
So when Bezos spends $5bn per year, that means he made $5bn per year (at least), so his tax statement should show him paying $2bn or whatever the top tax rate would imply.