The trouble with Doctor Strange is that he's not actually a Doctor.
So either you have a character who's a dedicated surgeon who discovers
magic and think 'fuck sick people, I can visit the astral plane!' or you
get a magician who performs magic tricks during surgery and the Marvel
movie is a 2 hour episode of ER. Both are terrible characters.
He is a doctor, he has a PHD, he's just a surgeon, and his hands don't work well enough to perform surgery anymore. His journey is that he starts out as an entitled douche, then loses the tools that he needed to maintain that lifestyle, so he goes on a bit of a journey and becomes a better person. Fundamentally it's not that different from Iron Man's journey, and that movie did just fine. Eventually he takes on the role of not saving a life or two per day on the surgery table, but saving everyone's lives in defending them from existential threats from beyond.
I would set the plot so that act I shows him as a broken man, a little like House at his worst, then flash back to before the accident when he was a total douche, boozing and treating people badly, but too rich and successful to care. Then the accident and cut back to the present. Montage of him visiting every possible doctor, including the crazy and imaginary kind, but none can bring him back up to where he needs to be. After any number of failures, he seeks out a Himalayan mystic, but passes out in the snow. He wakes in the Ancient One's temple, who puts him to work cleaning the place. As he works for him, Strange finds that his labors are flexing out his hands and making them more functional, and at the same time he's picking up a few magic tricks, including how the master uses his various tools like the Eye and Cloak.
After years in his service, Strange feels that his hands are back to the level they once were, and seeks to leave. He tampers with a device that he believes will allow him to travel back to New York, but instead it releases some deadly force into the temple, Dormammu or something. This villain throws him aside and engaged the Ancient One in an epic battle, eventually killing him. With his last strength, the Ancient One sends Strange back to New York, along with his cloak and Eye. After using the Eye, Strange finds that even New York is full of all sorts of magical weirdness that normal humans can't see. The villain follows him for the loot, and Strange has to learn to use the few tricks he's explicitly picked up, along with the new tools he's got, to figure out a way to trick the villain into a trap of some kind, sending him back outside the universe.
With the villain dispatched, Strange now has the choice to go back to his old lifestyle with his now repaired hands, or to take the legacy he's inherited and maintain the mystical balance. No sooner does he make the choice to take on the role of protector, donning the cloak and eye, than he receives a knock on his door, Wong on the other side with a giant bundle of tomes on his back. "Finally, you still have a lot to learn. . ." as he brushes past Strange into his home. Pull back to show that the house is the famous Greenwich brownstone, fade to black.