I think federation is just a design tool meant to solve a specific problem, much like decentralization, programming language choice, data structures, etc are more concrete software engineering ones.
I wonder if we might see a crytocurrency someday follow that same pattern: the chain is decentralized and public, but the miners are each replaced by authorities that a user can choose to accept (or not). The downside to this would be disagreements over who actually owns what. You'd only be able to make a transaction if both the buyer and seller agree on who owns the currency being exchanged.
At least then we wouldn't have the insanity of "whoever uses the most electricity is right".