I think the issue is so many sites load too much crap into their pages, for what should be relatively simple articles. The websites could have just written really simple/fast pages... but they didn't. AMP forced the issue.
Of course, google could have just favored really small/fast site that worked well on mobile... but this way they get the extra lock in.
Maybe because that's not the only thing it does? It is what Google likes to pretend that AMP is all about, but you're also handing over the control of your traffic directly to Google, and being awarded with the SEO boost.
That's significantly different than debloating your website and remaining in control of the traffic, but you don't receive the SEO boost as a consequence. Even if you make your website faster than it would be if you were using AMP (which is not that difficult to achieve), you're still being punished for not giving control to Google.
If you put your page on the web it is going to get cached. The http depends on this. You are not giving up control of your traffic. You never had it in the first place.
