There's something really not right there. Right click the bottom right status bar area, enable memory monitor and ensure you aren't running out of RAM or something. I use IntelliJ on an old Intel MacBook with a large Kotlin project and its performance is good. I never have to wait ten seconds for something like that. It sounds like you may have some old flag that's limiting its heap size or pushing it into GC thrashing or something. Definitely look at the IDE logs and see if you can track it down.
