One use case that drops out for free with #pubkey

You can can use your npub as a domain, forver, without paying fees.  You just have

npub.nostr or pubkey.nostr

And use their resolver to set up, and then look up the domain.  Click on it, and you are redirected to the domain.

This should be doable today, and if the NIP gets merged, many more clients can use it.  Decentralized DNS plus nostr identity.  Just by gluing two different web technologies together.