Isn't the entire point behind "language server" (guess it's referring to LSP - Language Server Protocol) that it gets rid of editor-dependent stuff?
The dream (as I understood it) was that people could write things like this, and it'll work out-of-the-box for a bunch of other editors, as long as they follow LSP.
It's not really about the editor. The editor (the LSP client) just provides support for telling the server what the user wants a definition for, and how to display that back to the user.
As a simple example, I'm learning japanese so I built a 50-line LSP server that just looks up definitions of a word under cursor in a dictionary. This is an almost-trivial server. Its only capability is to offer definitions when hovering a position in a text document. It works perfectly well in neovim with lspconfig with 2 lines of configuration. I'm sure it would be similarly trivial to integrate in VSCode, Emacs, etc.
Other non-coding uses of LSP that I'm aware of are spell-checking and grammar suggestions (LSP clients can display diagnostics), semantic syntax highlighting (e.g. for highlighting a markdown document), and projects like the one discussed here which just integrate more general-purpose AI.
The dream (as I understood it) was that people could write things like this, and it'll work out-of-the-box for a bunch of other editors, as long as they follow LSP.