Right, there was the Church of Corinth, the Church of Jerusalem, the Church of Ephesis, the Church of Hippo, of Thessalonia, of Alexandria, et al. And these remain alongside the Churches of San Antonio, New York, Mexico City, Paris, et al. That is why it was called catholic, or universal. It was Roman because everything was Roman. It was hierarchical because Rome was so, and society remains so today despite democratic theory. Christ remains the Head of the body that is the universal Church; but every organization of men demands a leader. (The ancient Hebrews begged for a king and the Lord provided a king.) The bishopric of Rome, being the seat of St Peter, was acceded this necessary highest office, the power-struggle with the Churches of Jerusalem and others notwithstanding, such struggles being inherent to human nature.
Our Blessed Mother loves obedience. The Lord, providing for us, will make use of all our errors. Keep the Faith of your fathers and mothers, whatever it may be, for civilization depends upon that; but do not despise the RCC for its rightful pastorate.