What isn't? We don't need someone to go "yep, they definitely blew up the stars" when we can literally see what happens on panel and occamz razor suggests we go with whatever makes the least assumptions which in this case would be them having been destroyed unless you can suddenly explain the disappearance of all the light in that region of the area Yes, it was said it was enough energy to destroy the earth. Which is vague as fuck and could mean its many times that destructive force. All that was said about Buu's death ball was that it was going to destroy the earth but we know it's way stronger than that. If we completely ignore the void feat being afraid of the sneeze is pis Especially after the show of force from the last chapter they went out of the way to demonstrate and Saitama being stronger than he was then isn't a contradiction for the feat nor is it where the author just "intended" them to be.