IntelliJ actually does (did) have quite solid vim emulation, at least from my experience of using it before going full into neovim (now on Emacs, btw)

Except when you go to any pane/window without code it stops using vim bindings

Yeah, that seems to be the general pattern across vi-emulation. However, back when I was on IntellJ stuff (pre vi-emulation), I was already quite deep into the plethora of keyboard shortcuts within IntelliJ, so although you couldn’t do everything with just vi-emulation, you could still do essentially almost everything without leaving the keyboard. Not the same as full blown vim, but it was a solid workflow in my eyes.

The main reason I switched was because of finances and hardware limitations, as I’m now rocking an 8GB M1 MBP