The Roman sect is just that. The whole Church is made up of the body of believers that have washed their robes in the Blood of Christ. Some from the Roman sect belong to the Church others do not. And despite what you think you are not sole proprietors of the sacrements. I receive communion on a regular basis well outside of Rome.
But it's too late at night to get into ecclesiology here (nearly 10 pm) and besides, ecclesiology is not my forte.
Let me just say the church cata-holos should never have been divided, splintered, split, fictionalize, denominationalized, or torn to pieces, because that is, I think, tearing apart the Body of Christ.
It is not His will, and never has been His will. He did say He wants there to be one flock, one shepherd.
I don't think it's fidelity to leave when things go bizarrely, incomprehensibly wrong, and things were never more bizarrely wrong than when the Apostles were variously hanging themselves, denying Christ to the servant girls, or hiding in the tall grass. If that were the right thing to do, the Church would have died out somewhere between the Cross and Easter.