In a dozen years, I think I've had a grand total of 4 clients (out of several hundred) that ever used PGP (despite recommending it specifically on project kickoff calls, particularly for communicating discovered vulnerabilities). I only had one who already had a key.

Outside of those few work examples, I don't think I've ever sent or received a PGP encrypted message. In fact, the only signed messages I think I've ever seen were mailing list messages from people who signed all their messages.