Maybe someone can enlighten me as to why old master Maul is viewed so weak here.? Where in canon does it state he has decreased so dramatically in power? I have yet to see it.
Because of his "loss" against Kanan? Maul has shown to lose to weaker fighters before due to his overconfidence. Because he lost to Ben Kenobi? In Disney canon, all the info we have points to Ben being stronger than ever before (the same quote implies the same for Maul).