Again, it's a fallacy to say that if there is no feats, they can't do it, especially when the narrative said otherwise. I mean, I can sit here and say that Goku can't destroy a planet because he never did it, yet we both know that is nonsense. As I mentioned, the only Super Saiyan forms, prior to Super Saiyan God, that had noticeable feats was Super Saiyan 3 that shook the Earth. Every other form of Super Saiyan has to scaled to who they were fighting at the time.
Or how about this: feat wise who comes out stronger, Namek Saga Frieza or Super Perfect Cell? Namek Saga Frieza destroyed a planet, while Super Perfect Cell didn't. In fact, he had to blow himself to attempt to 'destroy' Earth. Heck, Roshi and Piccolo both have better feats than Super Perfect Cell since both them destroyed the moon.