I'd say that has been true in the past (and is still mostly true today), but I think this will change in the future. I have been using lsp+treesitter for markdown editing and it's been an excellent experience. It's still early days, but with treesitter and lsp being as universal as they are I've been seeing a lot of people just experimenting with what's possible.

So yes, they are essential only for source code editing, but it's quite exciting to see what they can do for general text editing.

I'm looking forward to seeing Org Mode implemented as a language server. It's unfortunate that such a great general text organization tool is locked into the relatively small Emacs user community.

orgmode is so not a markup language and cant be served via lsp. its a whole ecosystem built on top of emacs. short of rewriting it, implementing it fully in another editor would require a sort of virtual emacs machine running in the background

Typescript or Rust are also not markup languages, and language servers for them allow for many interesting, non-trivial operations, so the model is capable.

Ergonomic keybindings would be a challenge though.

org-mode is more a program than a language. how would you implement org-capture or org-agenda through lsp?

I am curious, what features does an LSP server provide for such a simple format as markdown?

I'd say the most important thing is jumping to definitions. That's not terribly useful for standalone documents, but I use markdown for general note taking and it allows me to easily link other relevant notes. With that come a bunch of benefits, like autocomplete, finding all references, renaming/refactoring, hover preview, etc.

Other editors implement this specifically for markdown (i.e. Obsidian), but not needing to switch programs, as well as just having one set of motions/keyboard shortcuts has made a big difference in workflow for me. There are also a lot of other surprising benefits of treating raw text the same as code. I started using auto-completion with user defined snippets when writing Documentation (makes it much faster to integrate code blocks, tables, etc).

Many (if not all) of these things can be done in other ways, but I think it all just fits very well together and I enjoy that workflow tremendously.

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.)