The magician is not, traditionally, treated as a heroic character. It is rarely treated as a protagonist, and then often as the lead in a tragedy (e.g. Faust, Prospero). In the realm of fantasy, this held true; Moorcock's Elric of Melnibone is a tragic character. Heroic magicians are often secondary characters, companions and mentors to a warrior protagonist. In terms of popular culture this wasn't really broken until, once again, George Lucas brought us his Star Wars trilogy that showed us the journey of Luke Skywalker from innocent farmboy to ascendant Jedi Knight (and therefore a warrior magician). Even so, Luke was not truly a heroic magician until Return of the Jedi.
However, in the years between 1983 (Jedi) and 1999 (The Phantom Menace) a sea-change occurred in the culture. From where I sit it is (again) driven by gaming primarily and by Dungeons & Dragons in particular, taking the pulp fiction influences and moving them to a very different medium of entertainment where the sensibilities and motivations are something else.
Players--gamers--aren't keen to conform to dramatic sensibilities as a class. They are far more aligned with technicians than dramatists, and as such they will discard notions that interfere with their desire and pursuit of excellence in order to defeat and overcome the challenges put to them by the game. In terms of tabletop RPGs, playing a magician (until recently) was playing on hard mode; big payoff if you made it, but you had it rough for quite a while until your power ramped up, and even then one wrong move or run of bad luck and you were done.
Coming back into dramatic media, this would (in time) rehabilitate the magician into a suitable heroic protagonist because it had a proven path of character development and a ready-made pattern for plot development. In short, the gamers showed the dramatists where the heroic drama in such a character rested.
Don't think so? Start looking at the fantasy published in the wake of Dungeons & Dragons. While the big successes, even through the 80s, still held to the old tropes you could see their gradual shedding and changing. Now? Especially with the rise of paranormal romance as a genre, and the continuing influence of Star Wars through its Expanded Universe, a heroic magician protagonist is hardly unusual. Rowling's Potter was the moment that the dam burst, and in its wake many imitators followed. Comic properties began getting adapted, to varying degrees of success. (e.g. Constantine) Doctor Strange, therefore, is a comicbook example who was ahead of his time- and his time is now.
Yes, expect more in the future, and especially more high-profile ones. (Warner Brothers should have a Zatanna movie in the talking and pitching stage right about now, and the Shazam film hits this territory while presenting a Superman-style character.) Until another significant cultural shift occurs, this will increasingly be a thing.