You seem to forget that 2020 was Cathedral's first trip downtown during Thanksgiving weekend since 2014. Things happen in football, especially high school football, and sometimes it ain't all good. Cathedral lost a sectional game, while highly favored, to Roncalli when the Irish fumbled the ball 6 times, all by seniors. It's never a given. And teams can play "up" on a given night. Too many examples of that to list here.
Also you seem to forget that it was Bobby Cox himself who put Cathedral in 5A when they should have been in 4A.