How do you stop the oligarchs from changing the laws over time so that they don't have to pay those taxes anymore if they are the primary source of funding for every political campaign, lobbying group, and news media? How do you do it when many of our politicians are effectively oligarchs or share the interests of oligarchs? How do you even get that sort of taxation law passed under these conditions? The nordic countries accomplished this to a degree but those social safety nets they built are being eroded away as we speak. How do you put limits on capitalism when the capitalists are the only ones with state power?