If your argument is that decentralized ledger technologies cannot in their current state or perhaps ever entirely replace governments then I guess any reasonable person will just have to give that to you. And I doubt as many "crypto evangelicals" would actually argue with you on this.
Right; distributed smart contracts complement legal systems, like a road network complements a rail network.
Of course, that’s just the simple, “immutable logic” kind of smart contracts. The “updatable policy” kind of smart contracts are really just a way to encode and implement a legal system. (See: the regulation model in security tokens.)
I also think people complement smart contracts. The difficulty of building smart contracts makes me think people and human processes will be the glue that binds many of them together.