Yes and it has proof of work. The infrastructure is the protocol. Anyone can spin up a relay. Bitcoin also requires people to operate nodes. There is so much redundancy, that im willing to wager nostr will not disappear in my lifetime. irc servers are also operated by volunteers. The best things on the planet are run by volunteers. Keep crony capitalism away from nostr! That will be the only thing that can kill it! But hey, bootlickers will be bootlickers.