I have to use IntelliJ due to Kotlin codebase, but I'm still more of a fun of Emacs and I don't like Idea that much. I think IDEs somewhat lack the power that simpler tools have, which is automation.
One thing I miss from IntelliJ is programmability. That's why I still use Emacs on workplace for anything outside of Kotlin (git, grepping, note-taking etc). I even edit code in Emacs from time to time when it's easier to write a Lisp function which will batch edit code than doing keyboard macro.
Another thing I'm missing from IntelliJ is determinism. Everything is asynchronous, so the same combinations of actions can lead to different results, making automatisation painful.