Carol's struggle is clearly central to the film, though. It's about her self-discovery, casting off the shackles that the Kree have placed on her, uncovering the truth about herself. Talos doesn't really change or evolve, although our perception of him does. It's Carol who changes, learns and evolves. So I don't think that there can be much hesitation on that point (as to who is the protagonist). We do have this atypical element of the antagonist not being the character who plays the normal role of the antagonist in the narrative. But that is part of Carol's journey of self-discovery. She discovers that she has been the antagonist, essentially, but that she was a hero before that, and can be again.