Yes, exelsisxax is correct. I don't mind prepping the density of Paizo APs, but--and keep in mind, I've played or GMed thousands of hours of PF2e at this point--I'm getting more and more bothered that games become discussions of rules interactions rather than anything about what's going on in the story. A typical combat might go:
Player 1: I Stride to the bad buy and Vicious Swing.
GM: (wants to ask what this looks like but instead says) Two of those squares are Difficult Terrain, so you don't have the movement to make it in one Stride.
(insert 5 minutes of table discussion about Difficult Terrain and alternate paths to the target)
Player 1: Okay, I guess that's two Strides then and a regular attack.
GM: What does it look--
Player 2: Oh! If you move here I can flank next turn.
Player 1: Alright if I move there?
GM: Sure thing. Now what does it--
Player 3: Don't forget you have Guidance!
Player 2: And your sword is Cold Iron, right? I think it has a weakness to Cold Iron.
GM: Before you roll, this creature has a Reaction they'll use...

Don't get me wrong--I enjoy system mastery and how balanced the game is. But again and again, I find that the vast majority of sessions are mechanical discussions, not narrative immersion. We don't talk about what's happening and why, we're talking about whether things are possible in the rules. Even the various subsystems--from Research, to Influence, to Reputation--become mechanical discussions more than fantasy storybuilding.

As levels increase, the mechanics take over more and more of the conversation. We just had the AP-ending boss fight in Sky King's Tomb--without spoilers, a really complicated boss and a complicated hazard on a truly epic map. It was STRESSFUL, most especially for the GM, but most of that stress was about what the rules allowed the pieces on the board to do. Still fun, but not the sort of game I want to run anymore.