The asyncness of Intellij IDEs annoys me at times. I'm used (from emacs) to bashing out a series of key combinations in the expectation that the effects of one will be complete before the next is processed. There are cases in Intellij IDEs (can't remember specifics, I'm blissfully back in emacsland and don't anticipate using an IDE again in the near future) where that can result in the later keypresses being processed before the window pops up or whatever from the earlier ones.

Just a minor annoyance, really. It would be nice for emacs to improve on the async front, but synchronicity does have its benefits when interacting with humans. I sometimes find the lack of asynchronous behaviour annoying in emacs, but not very often despite using EXWM (so locking up emacs means locking up the window manager).