Have you ever managed to destroy the Papacy in Crusader Kings 3?

[I spent the winter writing songs about getting better]

Although this is a possible action you can take, I have a alas been unable to, mostly because Rome is so insulated from pagan areas. I'm currently in a game where I'm playing a Slavic pagan Emperor of Poland, so I might have a chance here. My goal is basically depose the Pope, destroy the Papacy, then convert to a "heresy" of Catholicism, and then attack the remaining Catholic countries in Europe and convert them to the Middle Ages equivalent of hipster Christianity.

I have managed to destroy the Caliphate before, but that's easier for a variety of reasons. I once managed to do it as a Zoroastrian of all things.

[I spent the winter writing songs about getting better]

The closest I've ever played to this game is Medieval II Total War. Should I attempt to play Crusader Kings?

Yes. Although it's just as much an RPG as it is a military strategy type game.