My personal non-AMP page weighs ~800 KB (including all images and JS). It still has no chance in hell competing against a 2.4 MB AMP page because I don't have Google's CDN.
Even if I follow all of Google's own performance guidelines, it won't help, as AMP pages load faster than text-only http://motherfuckingwebsite.com
> It's not "cheating" if it works in a real-world situation.
No. It's still cheating. Even if it works
First example I got (via searching Google for "news" and clicking the first AMP link).
AMP: https://www.google.com/amp/s/www.sfgate.com/crime/amp/Active... (2.4 MB, loaded in 760ms)
Non-AMP: https://m.sfgate.com/crime/article/Active-shooter-reported-a... (4.7 MB, loaded in 7 seconds)
The non-AMP page is twice as big and takes an order of magnitude longer to load. So, yes. I would _absolutely_ describe the AMP version as a "slimmed down performant webpage".
Could it be better? Of course! But users are still _much_ better off with AMP than without, at least in terms of performance. (And that's ignoring the fact that preloading is part of AMP. It's not "cheating" if it works in a real-world situation.)