Speaking from experience, they do. You just don't feel it until the adrenaline (and/or alcohol) wears off. If you punch someone hard in the skull, you're going to break your hand.

I’d imagine that sometimes they do - but in general you aren’t going to see the sort of technique you would see in competitive fighters in a street fight - the biggest risk here is usually hitting your head on concrete.

My buddy who used to get in a lot of fight was constantly breaking his hands punching dudes. It ev3ntually became a running joke, ala the song 'the winner'.