How can Stewart be the G.O.A.T if he never races? LOL?

Stewart took most of last year off. I think he was healing up some of his old injuries and rejuvenating his sporting lifestyle in order to become a better rider. (Something like that.) The outdoor series is brutal and takes a toll on a person and Stewart is a little on the frail side so they are trying to preserve him so he can perform at his best for Supercross.