The AR‘s are a lot better with dirt and such than they used to be. When I was in boot camp many years ago if the AR (M16) even saw a grain of sand it would jamb. They still aren’t as good at resisting crud and mud as an AK is but really have improved.
as far as a single defensive weapon goes, that’s a tough one. I have several that excell at one scenario or other. No one size anything fits all here.
I do not enjoy cleaning that much.
Talking about real, turn into the armory cleaning. Not just punching the bore and wiping down the BCG.