You could have substituted email for its encrypted, P2P, open-source counterpart for almost 30 years now. It's called PGP / GnuPG. What more do we really need?

You could have substituted email for its encrypted, P2P, open-source counterpart for almost 30 years now. It's called PGP / GnuPG. What more do we really need? It actually has more legal protection and formality, and way more clarity, than any centrally managed "E2EE" chat platform. We just need a really good app that uses SMTP as the underlying protocol to send messages that aren't MIME / HTML email, but rather are a simple new format for chat, and then start using email as a chat mechanism. There's no real reason why it can't be fast enough.