Federated verifiers who are kept independent out of band are strictly superior to proof-of-x verifiers for a distributed ledger: lower transaction costs, wider

Federated verifiers who are kept independent out of band are strictly superior to proof-of-x verifiers for a distributed ledger: lower transaction costs, wider feature space, less centralized. Proof-of-x tends towards one verifier, because it's an unregulated marketplace hence tends to monopoly. The one application where this isn't true is when regulatory risk prevents lawful verifiers -- i.e. illegal transactions. So, it's not coincidence -- proof-of-x will always be dominated by illegal user stories and desire paths as it is now, because that's where it's not strictly inferior.