Not sure how much clearer I can make the answer. Getting hurt is part of being a pro wrestler, but it's not an objective. Just like tackling someone in football. It can lead to getting hurt, but hurting someone is not the intention (unless you're an asshole). Injuries are just part of the game.
The chest smack, for instance, does hurt. There's no denying that. It stings, it makes a loud noise, it leaves markings, etc. Fortunately, those are the things that make for a good display. You can hear the loud clapping sound. You can see the red marks on a wrestlers chest. You can see the genuine anguish in their reaction after getting smacked. The audience reacts by saying "WOOOO!!!". That is the magic of pro wrestling. The whole point of training to become a wrestler is so that you don't hurt yourself or anyone else.