Rock stars are so much better than sports stars! Of course, I love rock music and do not care for sports that much. So to me they are absolutely better than sports stars. Sports stars are boring and rock stars are fun. They are always doing something crazy and are fun to watch.
Essentially, rock stars and sports stars are equal. They are both stars and it is impossible to determine a universal answer because which is better is going to depend on who you ask. Naturally, a music fan is going to say that a rock star is better than a sports star. But a sports fan will most certainly say that a sports star is better than a rock star.