I read your post as explaining where a "table variance" comes from, but you post in response to my post, and I wasn't suggesting any table variance? I was talking about that when I say something about the system, I really mean "as viewed through the lens that is the official adventures".To summarize, if small bonuses are likely to have a big impact on gameplay due to how your game is designed, typical GM decisions are also likely to have a huge impact on gameplay. This will increase table variance, and may be the reason why people have such different experiences from playing PF2.
I was talking about how you can absolutely create a campaign where the heroes doesn't experience a difficult fight ever. This is a simple fact. But it should not prevent us from stating "PF2 contains very difficult fights". After all, the APs are official. They follow the rulebook's official guidelines. If you set up encounters the "usual way" (monsters about your own level) you'll end up with easy encounters in 5E and hard encounters in PF2. Trying to dismiss that experience as "just one out of many playing styles" is not useful. There clearly is a difference.