The specification is so huge and complex. I was interested for a while but that faded fast when I started to dig into it. Also no browser-only support made it a no-go for me. Although I have seem a few cool hacks to run it in a webworker.
LSP server does not have to implement all of the spec to be useful. Just using document change and diagnostics allows to implement basic linter or spell checker.
Yep, the LSP mentioned in the blog post (I'm the author) only implements diagnostics and autoformatting for now. With just that you can already provide a lot of utility.
It doesn't actually, the "server" can (and in many cases does) run in the JS event loop.
Do you want the protocol to specify that language servers are able to run in a browser? Because that's very outside the scope of the protocol, which doesn't constrain the client or server implementations. LSP doesn't define the transport layer between them, just that they should use JSON RPC.
LSP and tree-sitter solve different problems and aren't interchangeable, it sounds like you were trying to pound a square peg into a round hole.
LSP doesn't (nor can it) specify anything that would make your life easier to use a language server in the browser. There are editors that provide clients and language servers written in JS, though.
