Yes, only a tiny minority of technical users will know what amp pages are and switch search engines to avoid them. But, a larger group will likely find the amp pages annoying, even if they can't precisely articulate why. This weakens google's hold on the market.
If the amp page displays what you expect, it works well. It it makes you click through, it doesn't.
Of course, users may or may not realize amp/google are the reason a site is broke.
Dunno how many people have issues like this though. Reddit was the main one for me, plus a few random sites having issues.
But it isn't always obvious how to get to the site from an AMP page.
Hmm. If AMP participation were voluntary, I would agree, but given how necessary it is to SEO ranking, Google deserves a large portion of any blame for broken content - They do not get a free pass to enforce usage of a protocol, but dodge the consequences of its implementation (which will always involve friction and some breakage).