Water is also wet.
Billionaires don’t pay taxes because they don’t have “income”. Their worth is in unrealized gains that remain untaxed until they sell, which they never will unless they have to. Instead, they can pass those assets to their next of kin after death, who also don’t pay taxes until they sell. Even if they do sell, they only pay taxes on the value gains since the inheritance, not since they were acquired by their benefactors. Generational wealth secured.