Full node count is the only real metric for actual decentralization. Hash rate going up means nothing and if miners unplug- another smaller miner that isnt in debt and has free/cheaper energy will just fill the void.
Discussion
The nodes that call the shots are the ones used by people receiving bitcoin in exchange for something else, because they withold the product/service/trade unless their node validates the received coins.
Miners provide immutability as a service, they have no hard power over the protocol.
Devs also have no hard power.
Only those who produce economic value and trade that value for bitcoin have power over the protocol.
I just watched your video. Interesting idea and first time I've ever heard it.
It feels way more nuanced than that. Whatever party spending or receiving is more desperate will conceive ground on what will be accepted as payment.. many factors in that.
Im sure there have been merchants who only wanted bitcoin cash for there service.. in that instance was bitcoin cash the real bitcoin?
I think the only thing that really matters (to me) is full nodes because without a vast network of individuals running them I wouldn't trust a protocol. And without trust any protocol is worthless.