Is that very different from "Whenever I find a site hosted through CloudFlare, I look up the origin server's IP address and link to that. Webservers deserve traffic, not CDNs."?
You cannot switch AMP cache to another vendor if you want Google rank your AMP site higher. [2] You also need a speical TLS certificate with the CanSignHttpExchanges extension that can only be get from DigiCert (for a price)[3] and not from Let's Encrypt [4].
[1] https://unlikekinds.com/article/google-amp-page-speed [2] https://stackoverflow.com/a/41683427 [3] https://web.dev/how-to-set-up-signed-http-exchanges/#step-1 [4] https://community.letsencrypt.org/t/cansignhttpexchanges-ext...
AMP being a subset of HTML, that does not look accurate.
Using a different CDN shouldn't significantly impact a site's income, but using AMP may have.