I think the real reason is that Google wants to build a walled garden, but doesn't want the walls to be noticeable. Even with AMP, they display a header that looks like a browser's address bar [1]
Also, on that page Google admits that it uses AMP Viewer to collect information about users:
> Data collection by Google is governed by Google’s privacy policy.
Which is probably their real motication for creating AMP.
[1] https://developers.google.com/search/docs/guides/about-amp
That's what AMP already did. This spec is better because it ensures publishers retain control over their own content, and doesn't confuse users by showing "www.google.com" in the URL bar for content that didn't originate from Google.
What confuses users is Google displaying a fake address bar [1] or browser displaying the wrong URL.
[1] https://developers.google.com/search/docs/guides/images/amp0...
Your browser controls the contents of the URL bar, not Google or the publisher.
Page and DNS prefetching exists, HTML exists, why not just link to the page on the original domain?
Exactly, this is the real reason why this abomination came into existence - all of this is masked as work for greater good all for those poor kids with limited network speed. As end effect everyone will suffer - user will never leave google ecosystem, he will remain on search page without even knowing about it, creator will lose control over his own content
Why should the user‘s privacy be protected toward the content provider instead of the search provider? The search provider already knows more about me.