Good developers can make fast sites (though that's not a given!!), but product managers will absolutely bloat your site.
"Add this third tracking/analytics tool";
"Add this custom ad format here";
"Oh this partner will give us tons of money if we put this widget on the page";
"Oh let's use Brightcove video player";
"Oh let's auto-play videos"; "drive-by A/B testing";
"We don't control this third-party 2MB image",
"The widget streams a 23MB .WAV file for background music that only auto-plays in mobile";
"Why build this in-house when we can just use this good third-party library?";
"Good third-party library costs too much, let's use this horrible but much cheaper one instead"; etc.
AMP allows you to tell your product manager: "Sorry! Not supported." Of course, with enough responses like this, a decision eventually comes down to not use AMP.
"Add this third tracking/analytics tool"; "Add this custom ad format here"; "Oh this partner will give us tons of money if we put this widget on the page"; "Oh let's use Brightcove video player"; "Oh let's auto-play videos"; "drive-by A/B testing"; "We don't control this third-party 2MB image", "The widget streams a 23MB .WAV file for background music that only auto-plays in mobile"; "Why build this in-house when we can just use this good third-party library?"; "Good third-party library costs too much, let's use this horrible but much cheaper one instead"; etc.
AMP allows you to tell your product manager: "Sorry! Not supported." Of course, with enough responses like this, a decision eventually comes down to not use AMP.