But where would someone even start with self hosting though? Even if you had your own dedicated computer you'd still have to get a domain name for your @ address. (I'm seriously asking, I've never looked into it). And then you're still at the mercy of your ISP (though OpenPGP would still help that).
Some ways I don't even know if DuckDuckGo should have an email service, or at least there should be more providers who offer privacy based email (to prevent the whole "I must use only services offered by one company" sort of mindset, like Google).
Start Page started https://beta.startmail.com/
which I guess plans to be another paid service.
was another option, and a free one. But having an email linked into the Tor network proved to be risky and they were indeed finally shut down. And that is another point of why "free" services don't/wouldn't last long- the blackhats, carders, spammers, etc would take advantage of it all too quickly. (and they still do for paid services, but it's harder)
Countermail is still what I use personally.