I’ve never had a conversation with a software developer where they didn’t know what vim or emacs are.
Ok.
But of those people who stick with vi for more than 6 months, how many of them have yet to hear of emacs at that point? Maybe 5%?
1) Emacs? What is that? Looks like it came out before I was born. No thank you, I need something modern.
2) Emacs? That's still around?! I remember that from my Vax days...
Either way, few of them would countenance the idea of using Emacs to do professional software development in 2020. The vast, vast majority of developers out there use either a large feature-rich IDE like Visual Studio, IntelliJ, or Eclipse... or they use Visual Studio Code.
4.5%. So not many but it's certainly "among."