Well she´s right in the sense that Gaga has been the most exciting thing in pop music since 2008, even if she´s declining commercially right now. She brought back the huge videos and she constantly releases music nobody else releases at the time. Artpop is a great album, like another comment said it is better than the other pop albums of the year. She has way more artistry in her than Beyonce, Rihanna, Katy or Milye, who are the ones who are supposed to be leading pop right now. So yeah, without her, mainstream music would be way less artistic.