Quite honestly, the concept never really made any sense to me, and often the load speeds were just as poor as the original website itself.
One thing that really bugged me was how disorientating it was for the user; on some AMP pages, you literally could not tell if you were on a legitimate website or some spoofed version. The AMP bar at the top was about as trashy a UI design as I've seen since 1997. And, God help you if you wanted to share the link - it was hard to know if the AMP link would be "persistent" or "sticky" enough to share, or whether you should go to the actual underlying web page (which the AMP bar did a great job of hiding) and share that.
But what is most annoying of all is that smart people at Google were kidding themselves that their botched up implementation of AMP was a great thing to have launched upon the world. It really was not. I bet it didn't really do much for their bottom line either.