> What exactly would be the point of native end-to-end encryption over PGP?

Basically just universal compatibility with clients and ease of use.

It's a bit how you could have all your important Word documents in a password protected compressed archive. But having password protection and zip compression native in OOXML is more convenient for users and guarantees than anyone with an OOXML compatible office suite has support to open the same documents (baring authentication of course).

    > The problem with email encryption is solving the authentication part, not the encryption itself.

It's both. Emails are typically transmitted in clear text so having something having them encrypted by default is a huge step up. (a bit like how people should be moving away from FTP and using SFTP, or SSH instead of telnet).

No. And I resent the fact that you couldn't be bothered to read past my first sentence.

The e-mail protocol (and I'm talking about the entire stack, from SMTP to the client's handling) is old and really not best suited for the modern way we send documents and modern security concerns. Which was the crux of my point.

So I'm not talking about replacing the paradigm nor ownership, just it's the implementation.