But the AMP pages give them preferential treatment in Google search results. I doubt they'd want to give that up.
I guess everbody sucks on this new, modern and JS-USB-enabled (thanks again Google!) web.
Pretty much, yes.
AMP compliance gets you a better Google search placement. So, every site is going to make sure they get their AMP placement and then funnel you to something non-Google.
AMP is an absolute cancer and its adoption would probably be 0% if google didn’t forcefully shove it down everyone’s throat. (And they are very good at learning from their own history, because that totally worked with Google+.)