You know when the tax bracket was above 75%, and 91% there were rich people that basically paid nothing in taxes? This was the result of existing exemptions in the laws.
You know the Rothschild? Rockefeller? In what period they made most of their money?. In those with the higher "rich taxes".
In fact that basically meant in practice that only a few could hold all the power, with no competition, by law.
It is very similar to what happens in Cuba today, when you can't earn more than 30 USD a month or so, no matter how good you are or how much you provide for the state. You could be the one responsible for the famous Che Guevara photo or a baseball player, you will earn millions that the State will take, and give you 30 USD.
An exception has been made recently for small business to this law, but of course some people in power are the gatekeepers to it(and you better pay them a significant part of your profits under the table for getting permission).
Of course the communist in power will spent lavishly your money because they can decide who spends what. No rich people in the country officially. Fidel officially has no money, extra officially it has billions outside the country.
Basic income means most of your money being taken away from you in taxes for someone else to spend for you. This has been already invented and tested before.