maybe best if we describe it this way: NIP05 is a human readable format that links to your designated pubkey... Because is technically just a link from one to another, and not an "encoding".
That said, I think it'll be useful one day that I can follow someone's nip05a nd in the event someone changes pubkey I can still follow that new key
For instance, I just mined this one #[4]. I had my current oen with leading 0s in the hex format, so now I got one with leading 0's in the npub format... but how can I switch it safely?