I agree in the ancient Rome for example gladiator fights were held just to entertain.
But from my own view point it's exist to satisfy myself. I love doing sports and the more I love if I'm in a team. Sure we are competing with the other team but the main point is that I play along with others and have fun (Of course if it's a cup the main point is the winning, but other times it means less for me). And if we win I'm happy yeah we made it together or after a very hard summer camp I couls say :"Oh my god, I survived. I never imagined I would be ever able to do these things, now I know I can make it, I 'm not that weak." Or in a dancing team, I'm proud and extremely happy if we finally could learn and make an acrobatic movement. I go two places for practice, these two places are very different. Where there are the younger teams the atmosphere is awful. They are doing it longer than me but they have no respect to our age... And yes they are competing, I think they even talk out us behind our backs. But at the other place everyone is friendly and we help each other out during the coreography now that's what I like. I hate that competing atmosphere. In my opinion my case is the minority, people love to compete and feel the victory.