I’ve also seen plenty of new editors rise and fall in the past 20 years - Komodo, TextMate, Sublime Text, Atom, etc.
Two of those editors are Mac-only, and only one editor is open source. I suspect if Sublime had become open (and cross-platform), it would be significant "player" in the editor wars. Atom has mostly died on the vine, thanks to VS Code. That doesn't negate any of the author's points about Emacs, but, aside from VS Code (and, I guess, Atom), there have been few efforts to create a performant[0] cross-platform, IDE-like editor.
[0] Insert comments about VS Code's performance here.