Vim can do all of the above pretty easily. In fact, I have a mapping for json pretty-printing, filtering it with jq; mapping for autoformatting with black or ot

Vim can do all of the above pretty easily. In fact, I have a mapping for json pretty-printing, filtering it with jq; mapping for autoformatting with black or other formatter depending on file type; a plug-in for undo history tree. I don't have configuration for running tests the way you do, but I know a guy who does something very similar in vim. I don't think the things you describe are the differentiators for the Great Editors. For me it's more their phylosophies that make them stand apart: despite the wide usage, vimscript is far more clunky, narrow-scoped and less powerful than elisp. Which means that stitching together something complex is hard and awkward in vim. Emacs is far more suited for complex processing due it's nature of a lisp machine. The chords are awkward though. So, "emacs is a good OS, but it lacks a good text editor".