Which begs the question of what happened to all those other winners?
Clarkson and Underwood both still have their careers, though they're nowhere near what they used to be. I remember Fantasia Barrino and Jordin Sparks, neither of which seem to be on the radar anymore. I couldn't even name any of the other ones.
Then again there are people who lost, like Adam Lambert and Chris Daughtry, who have somehow managed to have way more successful careers than the people who actually won.