Keith Medcalf said:
"just static content" would be more accurate ...
and using http rather than https
There were many attempts at this by Johhny-cum-lately ISPs back in the 90's -- particularly Telco and Cableco's -- with their "transparent poxies". Eventually they discovered that it was more cost efficient to actually provide the customer with what the customer had purchased.
One of the complications in this area is an extra layer of logging which could turn into privacy invasion. I'm pretty sure it was Comcast, but a quick search didn't find a good reference. Many years ago, there were a lot of complaints when customers discovered that their transparent proxy web site traffic was getting logged. Comcast said they weren't using it for anything beyond normal operations work, but nobody believed them. Shortly after that, they gave up on proxying. I'm sure the general reputation of modern Telcos and Cablecos for privacy invasion didn't help. -- These are my opinions. I hate spam.