Can you elaborate please? VSCode is literally the reason why LSP even exists

They turn your IDE into a distributed system with parsing and serializing overhead for every action.

Isn't that true for any editor with LSP support though, not just VSCode? And I personally consider that to be much better than the alternative solution of re-writing parts of the compiler to a different language to integrate them into the editor directly, like JetBrains does.

I was wrong. I meant Treesitter sucks in vscode

VSCode doesn't support tree-sitter at all, it doesn't "suck", it just doesn't exist