Erm, VSCode does all of that for Rust via RLS and the Language Server Protocol[1]. Heck, VSCode does even better than Android Studio because the pick common words in the source file as part of their auto completion. Things like comments, untyped parameters(ints, etc) all work much better in VSCode.

I'll agree that for Java VSCode isn't up to par yet but for many other languages it's easily at an equal level.

[1] https://github.com/Microsoft/language-server-protocol