Earlier quoted context omitted.
GPGTools, for example ( https://gpgtools.org ) I suppose I omitted the step of copying and pasting your recipient's public key, but that's not especially conceptually difficult, either.
That does look quite nifty. There's also keypair generation, which is the step that derails most people I think. Plus the fact that people have to grok the concept of public and private keys, and be able to distribute / not distribute them as appropriate. And revocation certificates. And public keyservers. And trust levels. Etc. I do think an organised, disciplined group might manage to get PGP working as intended, b…
Obviously, that's total conjecture, though.