if the protocol were to change, clients and relays would have to also be willing to adopt the change, almost if not all of which are open-source and easily forked if a large population did not care to pull in those changes. Sure there's always someone guiding the direction, but I don't know how much better you can get than that.
About the only ownerless protocol is Bitcoin (not Ethereum, Monero or any other one) and it still has an entity with soft power over it.