[the8472]

AMP still includes javascript that does many retarded things, including hiding the site contents until the JS is loaded, often from 3rd party CDNs. So if you're blocking the amp JS then the site just shows a blank screen, until some CSS animation trickery blends it in a few seconds later.

In other words if you use a content blocker AMP can be slower than the page would be without it.

[gregable]

AMP hides the entire page to avoid what is known as a Flash of Unstyled Content (FOUC). The document unhides as soon as a single AMP javascript resource loads, or an 8s timeout if that fails. That javascript is very cacheable and is often already in the browser cache to begin with.

[the8472]

The page is also readable without that script and browser engines already delay the initial paint. So this is entirely unnecessary.