At one point vim lacked asynchronous plugins. If a plugin was running a builder or linter it locked the editor up (from what I recall).

That fell apart when people wanted vim to do some more modern IDE kind of things like all the “… on save” stuff (build on save, test, lint, etc). I think LSP support is native in neovim as well.

I believe vim merged asynchronous plugin support a while back though, so I’m not sure how different they really are anymore.