Before this special, Goku’s parents were a blank slate. Akira Toriyama’s original manga simply portrayed the Saiyans as a warrior race wiped out by a meteor (later retconned to Frieza). This special gave them a face.
Frieza doesn’t even stand up. He merely flicks a finger, conjuring a Death Ball the size of a small moon. And Bardock, with a broken face and a defiant spirit, keeps flying forward. He throws his very last energy blast—a desperate, tiny spark—into the face of annihilation. Dragon Ball Z Bardock - The Father of Goku -199...
For decades, this special was considered "anime canon" but not "manga canon." However, history has been kind to Bardock. Before this special, Goku’s parents were a blank slate