In my opinion, Jesus was making a play on words regarding Cephas (Peter) when he said he’d found his church on Peter’s determination.
He did.
We read about it in the first third of Acts. After that, Peter’s founding role had been completed. Day of Pentecost, mission outside Jerusalem, and the vision about Gentiles.
Mission complete.
In short, just because Peter was specially used in the founding of the church doesn’t mean that an entire hierarchical position is initiated. That’s just a silly, and unbilical, addition to the text that simply isn’t there.
Amen.