Only DNS can mildly slow down Nostr at this point. And that is a short amount of slowing down. People could edit their relays and go on. In that case yes, having a Nostr Naming System would be cool to have as a fallback option. Then enough fallbacks later, it could be default.. .
nostr:note1n480q2mva32hkdqd8xm3vl0d630luz8850smt87tp46w7fm4vnjquqnaqs