My point is that it doesn't have to be visibly complex. gmail or outlook could automatically generate and store a public key for every single account transparently then just append signatures to the bottom of emails while providing the public key directory for their users.

Then any random client can hit keys.gmail.com (or whatever pseudo standard one wants for finding the key servers) cache public keys and on some TTL check for revocation/etc.

Then the only thing the user would have to know about is whether the from box is "green" indicating that the user was validated, "yellow" indicating an invalidated email, or "red" indicating a problem with the validation. Once the validation is complete via a back/forth exchange the clients then know they can encrypt emails to the destination, thereby turning the from field green on the next email exchange.

Sure people using those services would also be allowing the service to see their private keys, but for phone apps, or desktop applications the key generation portion could be done on the machine and only the public key pushed to the email providers keyserver.

Plenty of other email services (proton mail, symantec) make this very easy for the end user.

I would have agreed with this a few weeks ago, but given recent events you would be shocked at how many people are swarming into things like Signal. The average person is realizing that they don't get to choose what opinions are allowed and what are not allowed.

It's no doubt a reflection of my social circle, but it includes plenty of people that barely know how to turn their computer on. Many of them are asking me what to do to protect their privacy and ability to communicate.

If I were Keybase right now, I'd be starting back up development and cranking out some marketing right about now. That's a huge opportunity.