IMO, technically, it's the most important thing. Every other aspect of the protocol other than the pragmatism of a client-server architecture is non-critical. I don't mean to cheapen the other things nostr has going for it, but on a basis relative to id/architecture they are arbitrary.
Great read! It's exciting to see ideologically adjacent folks discover and embrace Nostr. I like his focus on "nature's" many attempts to evolve the relay structure. I think this sort of structure is probably inevitable