Apart from everything else, in the last few weeks I've seen a bunch of AMP pages that include at most the first few paragraphs, possibly just a photo or something, and a "read more on our website" link below. This is strictly worse than a world with no AMP: I have to load the AMP page, and then I have to load the real website.

Because of that I'm starting to seriously wonder if Google is going to end up declaring AMP a failed project (and, being Google, the prior probability was reasonably high in the first place), and then AMP is an uncleanable stain on the web, with www.google.com/amp/ URLs being kept around forever.