Me and Mike is not any harder to understand than Mike and I. It is harder for the speaker to always make sure they’re using the correct form, though. The extra effort for the speaker must also be considered. Sure, if you’re writing a book you should probably try to use the correct form, but in casual conversation it does not matter, and is more effort than it’s worth (at least in this case)
Intelligence is knowing that Scooby Doo taught us that the real monsters are the humans.