The unrealized potential of federation
Federated systems just don't work in practice because of inherent problems with them that don't have good technical&social solutions yet. Everything on the Internet (including Internet itself) degenerated from federation into monopolistic centralized services for a reason, and somehow people keep ignoring the evidence, and just keep trying harder.These problems are so fundamental and universal that you pretty much need "a new form of Internet" that solves them, so then apps running in it can compete with centralized services.So far the best stab at the problem is Urbit, but mostly because almost nobody else is even trying. Handshake and Holochains are another interesting projects in this space, but more of a pieces of potentially bigger picture.