The pope does not act or speak arbitrarily nor does he do so from within a bubble. He does so in consultation and prayer with other leaders of the Church.
I notice in the recounting of Mathew, you fail to mention that the remedy for one whose brother has offended him is to bring it to the church. And, who in the church would resolve it? The elders, the leaders, the priests, IOW the ones to whom Jesus was speaking when he gave them authority. Or did, as you seem to indicate, Jesus mean that we should air our offenses in front of the entire body of believers and then what? a vote? Jesus speaks here quite clearly of the authority of the church and its leaders.
Does the NT also not tell us that the Apostles appointed and laid their hands upon men, conferring upon them authority, in every community where they first brought the gospel? Or did they waltz in, proclaim the good news and then mosey along leaving in their wake no authoritative voice?
The authority of the Church is not dictatorial. Like in the US, though there is one president, his authority and council is done with others and not alone, but it his signature that makes policy final law.
>> I notice in the recounting of Mathew, you fail to mention that the remedy for one whose brother has offended him is to bring it to the church.<<
“Bring it to the church” the gathering of believers. The church is not an organization, it is a body of believers. Yes, there were designated leaders in the church but not a hierarchical structure, only differing levels and responsibilities of service.
Matthew 18:15 Moreover if thy brother shall trespass against thee, go and tell him his fault between thee and him alone: if he shall hear thee, thou hast gained thy brother.
16 But if he will not hear thee, then take with thee one or two more, that in the mouth of two or three witnesses every word may be established.
17 And if he shall neglect to hear them, tell it unto the church: but if he neglect to hear the church, let him be unto thee as an heathen man and a publican.
18 Verily I say unto you, Whatsoever ye shall bind on earth shall be bound in heaven: and whatsoever ye shall loose on earth shall be loosed in heaven.
19 Again I say unto you, That if two of you shall agree on earth as touching any thing that they shall ask, it shall be done for them of my Father which is in heaven.
Nothing in the above verses states that the, “church leadership” or “a church leader” is the final authority or “in charge”. The church as a whole makes that decision.