I think Google's AMP project is a step in the right direction, but it seems to me that it's not adopted enough.
A step in the right direction would be a proper subset of html/css without requiring more JS to load
Unfortunately Google has bound it to other questionable practices like hosting on their domain, but it’s still a step on the right direction. We need something like that plus a way to cache it on the edge servers in a portable fashion so that any CDN like Cloudflare could pick them up.
And since you mention Cloudflare, I searched a bit and found https://www.amp.cloudflare.com/
There are problems with AMP, but Google exclusivity is not one of those problems.