urbit's routing is hierarchical but also decentralized. Planets depend on Stars for their routing, stars depend on Galaxies (Planets can spawn Moons). Anyone can own one of these nodes and put them anywhere. I don't like their approach because of it's overly hierarchical nature, but it is an interesting hybrid. 
This is just an example of an "experiment" that maybe you haven't heard of? (Or maybe you have). The world is big and I don't presume to know of all the things people have tried but haven't taken off because of poor marketing or outright idea suppression by powerful centralized forces.