In my experience AMP website would always be missing features like comments or be bugged in other ways so I usually have to load the full website anyway. It just wastes my time and is one of the reasons why I switched away from Google search.
AMP performance was a huge win for me as a user.
I almost never wanted the "full experience" of a page. I wanted its core content, quickly.
I agree AMP is anti-competitive, but if publishers made their default pages as lightweight as an AMP page _felt_ then they would have far more of a leg to stand on with users in regards to it being anti-competitive.
https://bestmotherfucking.website/
Loads almost instantly.
https://www.cnn.com/2020/12/21/europe/russia-navalny-poisoni...
Takes almost 6 seconds to finish loading and settle (content stop moving around). Pre-loading is not the only reason amp is faster.
On mobile its even more dramatic.