I know more people who use terminal user interfaces for email than I know people who use Thunderbird, and I say that as a techie.
The UI still sucks, though, because people ask me what the .ASC attachments sent with all of my emails are and if I've been hacked. When I explain that's for encryption, they may ask how to set that up on their phones if they care, but most of them just look at me funny.
I do use email encryption at my job, through S/MIME, and that works fine. Encryption doesn't need terrible UI, but PGP needs support from major apps (including webmail) for it to gain any traction beyond reporting bug bounties.
The UI still sucks, though, because people ask me what the .ASC attachments sent with all of my emails are and if I've been hacked. When I explain that's for encryption, they may ask how to set that up on their phones if they care, but most of them just look at me funny.
I do use email encryption at my job, through S/MIME, and that works fine. Encryption doesn't need terrible UI, but PGP needs support from major apps (including webmail) for it to gain any traction beyond reporting bug bounties.