Some alternate viewpoints:
I don’t think AMP can be considered “open” technology. It’s a cunning scheme by Google, and other tech companies with resources to host AMP caches, to pillage/appify the WWW and divide the spoils.
It causes web publishers to lose control of their stack, because Google forces them to load a restricted version of the site on Google’s own servers (or the servers of one of their co-conspirators). It’s the end of server-side logs, because visitors never reach your server.
In the long run, the less control you have over your stack, the more at the mercy of those large companies web publishers will be. You end up sending your content onto their platform, and it is no longer really the open, decentralized WWW.
Google puts a back button on your site, so that visitors are more likely to go back to the Google SERPs than to explore deeper into your site (continuing this trend).
Signed HTTP exchanges spoof the URLs so that visitors don’t even know that they aren’t on your real website.
“Portals” are harmful to smaller publishers, because they allow large sites (that typically send traffic) to only show previews of the linked-to sites. It’s the new “can you open all external links in a frame?”
That’s part of the reason why it’s so bad. Google is not playing by the rules any more, and they are treating the Web as if it’s a Google product.
The only way Google can get people to use it is to strong-arm web publishers into adopting their format under threat.
AMP isn’t even faster than a hand-optimized page. Preloading-on-hover techniques (like in Gatsby.js) make loading pages as fast as an SPA, so I don’t think that the speed argument is convincing. It’s mainly about the business interests of some large tech companies that have the resources to host AMP caches.
A little extra traffic in the short term might sound attractive, but I don’t think it’s worth selling out the future of the Web. Also, I’ve read some comments from people who haven’t noticed much increase in traffic after implementing it. See also:
Sorry for the rant. Maybe Google will eventually win and all of our “websites” will become little more than pieces of content hosted on the networks of a few companies’ AMP caches, but I think that there is still a chance to stop it.