[cbdfghh]

The solution is very simple.

Google's spider uses headless chrome which runs Javascript (to index flash and Ajax content). Why can't they detect how long it takes to run your page before getting useful content?

What about just penalizing Javascript?

What about penalizing download size?

[majewsky]

Websites already can detect whether the client on the other side is Google's spider (either by checking for the well-known IP ranges, or by looking at the User-Agent). So they could supply a fast, cached version to Googlebots, and thus appear faster than they are.

I can see why Google would do this AMP thing. It's much easier to detect fast websites through positive rather than negative evidence.

[x0x0]

That's cloaking, and doing much of it will get you severe penalties.