>The real problem is sending email. Plain text email looks like trash in any modern mail reader. Any recipient will wonder why your email is broken. On a desktop client the lines will be way too short. On a phone, too long.

I disagree on "too short" lines being a problem for desktop, but in any case, it is quite possible to send plaintext mail without 70-column line breaks. How I do so in VM in Emacs: https://lists.nongnu.org/archive/html/viewmail-info/2020-05/...

I've had to stop 25 years of muscle memory of M-q while writing a message, but otherwise the solution seems quite satisfactory.