[user5994461]

Really hard to use tools and half obsolete by some metrics.

Vi predates keyboards with arrow keys and numpad. You can do most of what vim can do in any editor if you can use your keyboard effectively. Then there is the question of VI vs VIM. Some schools force students to use VI, which is really a different and antiquated beast.

LaTeX lost a lot of relevance since Office 2010, that added a great equations editor and better handling of sections/subsections.

[tasuki]

You totally can't do "most of what vim can do in any editor if you can use your keyboard effectively". For example: fXctX - find next X on current line, change to next X. You can, fortunately, get a pretty decent vim emulation in various IDEs.

TeX still renders equations better than Office does. Also it's programmable.