This is a good read. I think it’s a good solution if it can be implemented properly. Are there applications you know of that allow you to personally (manually) encrypt text and communicate with another person like GPG does?
You should not be doing manual communications as that opens the door for human error and is time consuming. Also these cryptography protocols are far to complex to easily be used for text.
And using these apps is not always an option. I like simplex, but sometimes email is one of the only options. PGP can be used agnostic of the technology used for transmission, and that’s exactly what we need to keep more people private instead of forcing them into a few select applications. If Diffie-Helman can’t be used in a transport-agnostic fashion then I do not see much progress in this direction.
Just keep in mind PGP is weaker in the sense that it is easier to break due to its shared key.
Email itself is not exactly a secure protocol