OK, how do I set up efm-langserver with Neovim? Good luck! You could probably use a plugin, or maybe not. You'll need a way to install LSP servers. nvm-lsp-installer? Nope,that's also deprecated, use Mason. OK, MasonInstall Black. Wait, it's not formatting anything. Oh, you might need nvim-treesitter. Um...ok, but that's installed already. Ah, you just haven't configured it correctly...here is my setup (pastes 300 lines of Lua or vimscript with zero context as to where you are supposed to load it)....Why are you using efm-langserver? Formatter.nvim is all you need! What? That's old hat! You should be using neoformat!
If you mention Ale or coc.nvim...they stare at you as if you have just stepped out of a time machine from the 19th century.