AMP is faster only for poorly-optimized JS-heavy pages but the design is fundamentally flawed to require all of its own large amount of JavaScript to run before anything displays, whereas most of the traditional bloat doesn’t block rendering. That means any optimized page - Washington Post, NYT, etc. – loads noticeably faster even before you factor in how often you need to wait for AMP to load, realize that some part of the content is missing, and then wait for the real page to load anyway.
That design forces it to be less reliable, too: before I stopped using Google on mobile to avoid AMP, I would see on a near-daily basis failed page loads due to the AMP JS failing in some way and when it wasn’t failing it was still notably slow (5+ seconds or worse on LTE). Since all of that JavaScript is forced into the critical path, anything less than unrealistically high cache rates means the experience is worse than a normal web page.
WPT examples:
https://www.webpagetest.org/result/200704_GR_62165b7f695e300...
https://www.webpagetest.org/result/200704_5F_f5c36a7c41cf4c2...
