I think GNU Emacs was released in 1985, but Emacs existed before that. Similar to vim and vi relationship.
In fact, Emacs was first implemented as a plugin (a set of macros in the language of the time) for a now forgotten editor called Teco, which was one of the first, if not the first, programmable editor ever.
Started with Gosmacs. Working in the CMU graduate terminal room with the man himself. I was just a freshman undergraduate, but a graduating student gifted a coveted X1 key to me. Mostly coveted due to the coke machine.
[1] why on earth would they go through the traumatic change of reprogramming their muscle memory after so many years? it would be like a wizard that voluntarily gives their power away. like a father sacrificing his own child.
Also, conversely whom Emacs is attracting these days. One interesting data point i came across is this philosophy dude protesilaos.com/ . Amazing youtube videos on Emacs and he has unique view from the point of philosopher for Emacs.
Apparently, the downvote restriction to wise users doesn't prevent some of them from being trigger happy. Maybe the release date stated above is wrong but I'm shocked to see this kind of comment downvoted.