Ah, if LSP is what parent meant with "VS code plugin compatible layer" then what you say makes sense, I personally also moved from vim to neovim mainly because of better LSP support.

But I understood "VS code plugin compatible layer" to mean there is something that lets you run VSCode plugins with other editors, which is what I haven't seen anywhere (yet?).

Except Emacs doesn't have "plugins". They are called "packages" and not plugins for specific reasons - they are more like libraries than plugins. In Emacs, one can change/override the behavior of any function (built-in or third party) with some enormous flexibility not easily achievable in other editors.

You are probably referring to language support plug-ins.

IIRC, debugger support for java needed a component from one of the official plug-ins.