Oh, but everyone does have to be a part of the private system. When the private sector goes crazy as in 2008 it drags everyone into an economic ditch. Moreover, it is only when the private sector buys up the government that the few rule the many for the benefit of the few — think K Street mob and its Russian connections.
Without a near perfect balance of socialism and capitalism a lot of folks get screwed. With unfettered capitalism you only have banana republics and Putinism, which is the Donald’s preferred model.