I wish they would... boost websites with < 1mb of html+css+js payload (exclude images). Extra points for optimized images for mobile by default, with upsizing for high density or larger displays.

Google could very well have given huge boosts to small/fast websites, and then the sites would have had to figure it out wrt advertising and bloat. It would have been a much better result.

They could, but then we'd see a lot of cheaters even there, AMP is very locked down. I don't like the market position abuse either, but the other parties are far from guilt free.

Of course SEO will never end. But if the question is how to improve the open web, then turning the open web into a Google property is not an answer.

Signed exchanges are a thing, I don't see how Google intervenes there more than just providing the AMP standard.