The church is founded on Christ, the Rock.
Peter, the guy you claim as first pope, even says so in his letter.
1 Peter 2:4-8 As you come to him, a living stone rejected by men but in the sight of God chosen and precious, 5 you yourselves like living stones are being built up as a spiritual house, to be a holy priesthood, to offer spiritual sacrifices acceptable to God through Jesus Christ. 6 For it stands in Scripture:
“Behold, I am laying in Zion a stone, a cornerstone chosen and precious, and whoever believes in him will not be put to shame.”
7 So the honor is for you who believe, but for those who do not believe, “The stone that the builders rejected has become the cornerstone,”
8 and “A stone of stumbling, and a rock of offense.” They stumble because they disobey the word, as they were destined to do.
I have been taught that Christ is the cornerstone of the church, and that the prophets and apostles are the foundation built into that cornerstone. (Using, of course the “building” metaphor.)