So says Rome. Rome says it is infallible, but that is not biblical. Tradition is the claim and I have a feeling you know enough scripture to know what Christ thought of man's tradition. I wish the Roman Catholic Church well, I believe there are lots of good Christians within and without the Roman Church.
I "hold fast to the traditions" that I've been taught (2Thess 2:15), ostensibly different from the traditions that gave rise later to rabbinic Judaism which is what the Lord was critiquing.
Isaiah 22:19-23 clearly describes the office of "steward" or keybearer, that is, "prime minister":
19 I will thrust you from your office, and you will be cast down from your station.
20 In that day I will call my servant Eli'akim the son of Hilki'ah,
21 and I will clothe him with your robe, and will bind your girdle on him, and will commit your authority to his hand; and he shall be a father to the inhabitants of Jerusalem and to the house of Judah.
22 And I will place on his shoulder the key of the house of David; he shall open, and none shall shut; and he shall shut, and none shall open.
23 And I will fasten him like a peg in a sure place, and he will become a throne of honor to his father's house.
There should be no issue between you and I regarding the meaning of the symbolism of the keys. The question should be, how do I know that this privilege was not only granted to Peter but to his successors in the Roman See? I know it because of the traditions that I have received and hold fast to.
The Catholic Christian belief in the Petrine Primacy of the Bishops of Rome is solidly grounded in Scripture and in the Tradition we have received, and hold fast to.
I wish the Roman Catholic Church well, I believe there are lots of good Christians within and without the Roman Church.
I agree with your last sentiment. I thank you for your consideration.
-Theo, live from Afghanistan.