Could we speed the Internet up with more generic caching?
I'd theorize that a decent percentage of all Internet traffic to residential ISPs is made up of HTTP requests for highly cacheable resources. However, it seems like the mythical idea of an automatic caching HTTP proxy at the ISP level never really materialized. Perhaps that was possible in the HTTP days, but HTTPS makes it a challenge.
How much better would Internet congestion be if there was a way for ISPs to cache commonly-referenced resources? They could even be video resources - if Netflix requests its videos across an HTTP connection by identifying a single common resource (a URL everyone will access who plays the video), then an ISP could simply cache the URL and serve it locally.
It seems like HTTPS is a barrier to schemes like that. Instead of an ISP running a generic cache for commonly-referenced resources, each website provider needs to run a local POP that's trusted and knows just their content. (Though maybe Cloudflare like solutions are possible where the POP is not fully trusted.)
If we set HTTPS aside for a moment, could we speed the Internet up with caching? How much of the traffic to saturated links are requests for the same content over and over again?
Is there a conceptual way to achieve some of the privacy benefits from HTTPS while allowing an ISP to cache content in a generic way? Or could an ISP offer a discount for using HTTP traffic instead of HTTPS, and then cache content in a protocol-compliant way?