Yeah, I chalk this up to broken feedback loops. A separate but related problem, is that in most places it works roughly like G = TI, with a fixed T (tax rate),

Yeah, I chalk this up to broken feedback loops. A separate but related problem, is that in most places it works roughly like G = TI, with a fixed T (tax rate), so that G (government budget) is a function of I (income). The tax just works like a resistance to accumulating wealth, no matter how much the government actually needs in order to function. It would probably help if we capped G instead, i.e. T = G/I.