The Catholic Church is quite good at constructing massive theological arguments out of single lines in Scripture.
Papal supremacy = And I say also unto you, That you are Peter, and upon this rock I will build my church;
You think papal supremacy is based upon one single line of Scripture? Wow.
First, it’s not one line. Jesus also gives the keys of the kingdom to Peter, He prays for Peter individually, and charges Peter individually with strengthening his brothers. He also commands Peter to feed, tend and feed His sheep. There is also the time in the Council when Peter declares a teaching, and all fell silent. That and Peter being mentioned more than all the other Apostles combined.
Second, papal supremacy was recognized when the Bible canon was determined (at Carthage in 397 AD). They recognized that their determination must be affirmed by the Pope.
It was also determined that besides the Canonical Scriptures nothing be read in the Church under the title of divine Scriptures. The Canonical Scriptures are these: Genesis, Exodus, Leviticus, Numbers, Deuteronomy, Joshua the son of Nun, Judges, Ruth, four books of Kings, 3 two books of Paraleipomena, 4 Job, the Psalter, five books of Solomon, 5 the books of the twelve prophets, Isaiah, Jeremiah, Ezechiel, Daniel, Tobit, Judith, Esther, two books of Esdras, 6 two books of the Maccabees. Of the New Testament: four books of the Gospels, one book of the Acts of the Apostles, thirteen Epistles of the Apostle Paul, one epistle of the same [writer] to the Hebrews, two Epistles of the Apostle Peter, three of John, one of James, one of Jude, one book of the Apocalypse of John.
Let this be made known also to our brother and fellow-priest Boniface, or to other bishops of those parts, for the purpose of confirming that Canon. because we have received from our fathers that those books must be read in the Church. Let it also be allowed that the Passions of Martyrs be read when their festivals are kept.
They note that the Pope (Boniface) must affirm their declaration for it to be authoritative.