I think you are sadly mistaken.
(That is probably true of Katy Perry, though.)
If her music sounds exactly like the aforementioned bubblegum pop, what's the difference?

Either way, a large percentage of both ladies' output lately has been written/produced/whatever, by Max Martin and Dr. Luke, as has that of Kesha (I refuse to acknowledge that stupid dollar sign), Britney Spears, Avril Lavigne, Miley Cyrus, Kelly Clarkson, Rihanna, Taylor Swift, Justin Beiber, Maroon 5, etc. Between the two of them, they have co-dominated pop music since the early aughts. Make of that what you will.