“I will give you the keys to the kingdom of heaven. Whatever you bind on earth shall be bound in heaven; and whatever you loose on earth shall be loosed in heaven”. The passage is stating that Jesus is giving Peter an important role in the church.
The importance of the papacy is to keep unity in the Catholic Church. Papacy can be described as a unique instrument of human governance that no other institution uses that combines both spiritual and political authority.
Pope Leo the Great used biblical, historical, and legal arguments to assert the primacy of the pope among all bishops. The Council of Florence, Fifth Lateran Council, and First Vatican Council where all reaffirmed papal primacy.
One difference between the two councils was that the Second Vatican Council began its teaching first on the ministry of the bishops and then addressed the pope in relationship to the bishops. Legal documents addressed how the bishops would rule and bring unity to the church.
I have neither given nor received unauthorized help on this work.