Yeah, I think this is exactly it. Just like web developers don'' t care about disabled people until law threatens penalties, they didn't care about performance until Google threatened penalties.
The question is - who else could provide same incentives as Google? How could an independent, non-corporate entitiy create the same pressure?
The other answer is "Browser makers"... but that's also Google. And maybe Mozilla, which is arguably the "independent, non-corporate entity" you'd like.
Really though, this works because Google has the technical chops to make it work and the positioning to make people want to do it. I cannot think of a single "independent, non-corporate entity" that's both positioned to do this and capable of it.
But that's not an appropriate role for Google. They aren't, and shouldn't be, the web equivalent of fashion police.
AMP avoids all of that. It also brings security benefits by getting rid of basically every tag that can be used to mount attacks on the browser.
Also, it's been known for quite a long time that users like faster sites, resulting in much lower bounce rates. Was that not enough for you to optimize the hell out of your site? It's been my experience that in a lot of companies, it isn't enough. Marketing or publishing or whichever department can attach dollar amounts to the tracker or ad or whatever they want to add, and devs can only handwave around experience.
It's not a winning proposition.
It would be ridiculous to down-rank the exact thing the user is searching for just because the user would have to wait 800ms longer for that information. Or up-rank something the user isn't looking for just because it loads faster.
The best Google can do is bluff about how much perf matters.
It may just be unfounded cynicism on my part, but this does not sound like a better web experience. It sounds like the web circa 2009-2015. It sounds, to me, exactly like all the things we'd like to get away from with something less intrusive than AMP.
That speed matters to user behavior has been known for a long, long time. This knowledge existed long before AMP did. It had surprisingly little effect on how pages were implemented.
So perhaps our princess is in another castle.
To my thinking, ahat AMP does is create a political context that enables developers to push back. By setting an unambiguous standard and clear advantages to complying with it, developers have a weapon to push back next time Marketing wants to ad fifteen trackers or whatever. This is leverage that just was not present previously, and it can change decisions.