Ah you do have a point. I think that the supporting characters will be nothing more than that. supporting. the main character really doesnt need anyone, as he or she will always be the one who gains their power and experience in one episode's time while everyone else gains it in one week's worth of episode's time.
Eventually, the story will come back and bite itself in the ass, and the supporting characters will no longer continue to develop, leaving the anime as a one man show, as almost every anime with 55 episodes or more tends to do.