I don't know why no one thought of a PGP-nostr bridge so far. The social features of nostr seem perfect to share and trust pgp public keys.
bUT whY nOt jUsT uSe nOStR native cryptography? Well, because pgp is still ubiquitous and wildly used in e2e email, in software distribution, darkweb, etc.
The same way we set lnaddresses, in our kind0 metadata, we can set a field for a pgp pubkey. No need for weird keyservers or DNS and webserver dependent WKD. Just query nostr relays.