> PGP key discovery is hard to do securely. Do you just trust what’s on the public keyserver? Do you use RFC 7929?

In the case up above in this thread branch of the poster's bank not emailing statements because it is not secure, key discovery would be easy. The bank would have a form available only when logged in to their online banking site to enable statements by email with a way to upload your public key.

My guess is that for most people who could benefit from emailing encrypted documents it is similar. They have a good secure channel to give the other party their public key.

I'd rather that something better than PGP be used though.