> Yes, 34 years and no plans to switch.
It's 26 years for me. Emacs is I believe the oldest software I still use. I started on an SGI Irix in 2000. I used it also on HP-UX, Solaris, Windows, MacOS, and of course all varieties of Linux
> Emacs cursor movement keystrokes are quite widely supported elsewhere too which use GNU readline or implement at least subset themselves.
And many keystrokes work on MacOS, too. That was a pleasant surprise when I got a Mac laptop for work.
One advantage of vi is that even though emacs is available on all those systems, vi is actually installed on all of those, setting aside windows. If you know rudimentary vi you can walk up to any of those machines and edit a configuration file well enough to work.
It's quite difficult to find software older than Emacs in widespread use. Emacs is one of the "original" software, the first GNU software for which the GPL was created. It competes with vi, whose direct lineage has been broken (nvi and vim are reimplementations).