I worked for a major news publisher and had to get my team to implement this piece of junk.
Imagine you have a website and a customer does a google search to find your site and then clicks on your link in the search result. Instead of being taken to your website you are just shown the content within google. That way, the customer does not get to actually visit your site at all.
So news outlets pay a lot of marketing/Branding dollars to get people to their sites. They also have commercial agreements to show ads to visitors and they also have paywall funnels on their content. You can imagine how pissed they are when google serves the link to the article and the visitor never makes it to the site.
So you might ask why would a publisher bother to implement amp in the first place ? Well because we were told that if we don’t do it then google will penalise our search result ranking by rewarding improved rankings for those outlets that had amp pages.