Fact: if the entire consensus mechanism as it was designed, is decided by 20 entities, it is not a peer-to-peer CONSENSUS SYSTEM any more. And that it the current reality.
Which, sadly, implies it's a failure. "The system is secure as long as honest nodes collectively control more CPU power than any cooperating group of attacker nodes.". Course one could "argue" about what the definition of "attacker" is but it is what it is at this point.