Not going to rehash what other people are writing about PGP, that could be a much longer conversation. But it's not just PGP that's the problem, PGP just happen

Not going to rehash what other people are writing about PGP, that could be a much longer conversation. But it's not just PGP that's the problem, PGP just happens to be what people are using to encrypt email. If it was just PGP that was the problem, we'd use something else to encrypt our emails and it would be fine. But the problem is that any system that works like PGP where we're primarily encrypting message contents, where we're not thinking about stuff like forward secrecy -- that's not good for email. Email itself isn't good for that because email doesn't really lend itself to E2EE, regardless of what you use to do the encrypting and key validation. So you could have a version of PGP that was amazing and brilliant, and it still wouldn't really be a good fit for encrypting email, because email is not a good fit for encrypting email. The entire structure of how email works makes it difficult to do encryption in a user-friendly, accessible way. I am also pretty skeptical of PGP (see some of the other comments), but that's not specifically why I mentioned it in my original comment. I only brought it up because most email encryption schemes I see are using PGP, and I don't think that PGP miraculously solves the problem. It's not good enough to paper over the fundamental flaws in email itself.