Half-joking, but I think it is actually over-estimating the vim user base because there are so many things to search when learning to use vim, whereas the others are much closer to a traditional word processors.
Apart from that, Emacs usage mostly correlates how much of text heavy tasks a programmer is doing. Most people tend to write tons of shell/perl/python scripts and take a lot of time recreate the magic of emacs outside it, Sadly most of it is also throw away effort with a lots of manual effort in between. Sometimes its entirely manual effort because eventually you need to learn Perl regexes, or sed or awk really well, and that's another black hole in itself. To me that's kind of a gap in developer training itself. If you are wasting man-hours to weeks doing what should be done in man-minutes you probably have a huge gap in the way you are used to thinking about how your work in general.
Growth of Python is a big problem for programming community at large. It's a tool largely designed for beginners and people refuse to move beyond that. What's worse they also carry that kind of thinking to any tool they want to use.
Developers are generally bad at automating our own work. We wish to liberate accountants and ware house workers from drudgery. But rarely do we look at our own very work the very same way.
Using git with vim also seems a popular search combo.
Personally I am amazed that the younger generation are keen to learn vim. I don't see why as I have gone the other way to only use phpStorm for editing in earnest. For me using vim for code instead of phpStorm is a bit like handwriting instead of typing, a definite loss of formatting and neatness.
The reason I find modern interest in vim so amusing is that there is no compelling excuse to use it. In the olden days when you had to queue to use a terminal in a computer room to enter code you had handwritten on paper there were no 'nano' or other editors, you had to learn and use vi.
I don't believe vi is quicker than a full size IDE but I still use vi, find and grep because I don't fully trust these new IDE tools and I am fairly dyed in the wool as a command line user.
The tools I don't fully understand are the textmate, sublime, notepad++ and other middling editors that don't offer the brilliance of vim or the possibilities of a phpStorm grade editor.
Obviously its php specific features aren't relevant here since we're discussing editors (or development environments) in general.
Personally I find that most IDEs are far too language specific, and I can't possibly invest the time to learn an IDE per language when there's so many languages I regularly need to edit (and probably yet more in the future).
VSCode isn't half bad, as it has plugins for just about everything, but it's still a juggernaut in terms of software size. None of the jetbrains product I've used had decent plugins for all the languages I need.
And of course none of these work over a purely terminal ssh connection, which is a bit of a deal breaker for me.
Definitely not trying to convince you to use vim over your favourit IDE, I'm just currious what your top 10 missing features are.