Reason #2

During the timeline of The Hobbit Gandalf and the white council put forth their power and drove Sauron (a.k.a "The Necromancer" as mentioned in the book) out of Dol Guldur,Mirkwood. You gotta be packin some magical heat to drive out the dark lord himself, and NO, the dark lord is not Voldemort; Sauron was the dark lord 50 years before Voldemort was even a twinkle in J.K Rowling's eye

.Gandalf vs The Balrog, Khazad-Dum