I'm very surprised by these comments...

I regularly review code that is way more complicated that it should.

The last few days I was going back and forth on reviews on a function that had originally cyclomatic complexity of 23. Eventually I got it down to 8, but I had to call him into a pair programming session and show him how the complexity could be reduced.

Someone giving work like that should be either junior enough that there is potential for training them, so your time investment is worth it, or managed out.

Or it didn't really matter that the function was complex if the structure of what's surrounding it was robust and testable; just let it be a refactor or bug ticket later.