If Google had not focused on making it possible for publishers to earn money from their AMP pages, why would any of them have been willing to put in the effort to rewrite their pages?

With any sort of grand proposal like this, you need to think about all the different people in the ecosystem and why they're going to be interested in moving over to your system. I don't think AMP has really succeeded, but without having publishers on board it would have gone absolutely nowhere.

(Disclosure: I work on ads at Google, speaking only for myself)