I had been told (and I have 0 special knowledge here, this is just what a consultant in this space explained to me a few years ago) that AMP boosted your placement specifically because latency was a scored and important factor.
As such, all you needed to do to get similar rankings was use any sort of CDN hosting for your page and you would get similar results to using AMP.
Also, it sorta seems to me like the author is complaining, "I can't just do a minimum effort AMP page for the search juice, I actually have to make a functional AMP offering or not use AMP at all." Strictly as a consumer, I feel like maybe Google is doing me a favor while telling off a publisher.
As such, all you needed to do to get similar rankings was use any sort of CDN hosting for your page and you would get similar results to using AMP.
Also, it sorta seems to me like the author is complaining, "I can't just do a minimum effort AMP page for the search juice, I actually have to make a functional AMP offering or not use AMP at all." Strictly as a consumer, I feel like maybe Google is doing me a favor while telling off a publisher.