Each charges for its services. On a private platform like the App Store, developers have accepted that 30% is the tax they have to pay to Apple for all the services it provides to the economy it supports. People also take for granted that platforms like Uber and Lyft take a cut from their drivers, and Amazon a cut from its resellers. So too, in a democratic society, people tax themselves to pursue common goals, to finance the platform upon which society builds. In a closed society, those in power extract rents from those who use the platform. But one way or another, we must pay. The question is how much, and whether we think what we get for what we pay is worth it.