LSP goes far beyond source code. It also covers an increasing number of markup and configuration languages, and there are even language servers for prose that perform grammar checking and offer style suggestions.
Problem is, all of that sounds like a lot of crap to have running, and a lot of dependencies. That is not everyone's thing.
I like to be able to type "ps" and see one process for my editing session (with a low VM footprint in the low double digit megabytes at most, which had a startup time in the low hundreds of milliseconds.)
