I think the answer to that is that the days of local caches being useful are long gone. The top traffic count on many networks ends up being things like Youtube, and very few people are going to see the value in attempting to locally cache that sort of data.
Even if served over http, tonnes of traffic is uncachable anyway due the increased use of dynamic resourcing. Even this basic looking HN page will end up uncached by Squid because I'm logged in, regardless of https being in the picture.
As for performance, I've played around with benchmarks using Goad on a micro tier EC2 instance and never found an appreciable difference between http and https.
Even if served over http, tonnes of traffic is uncachable anyway due the increased use of dynamic resourcing. Even this basic looking HN page will end up uncached by Squid because I'm logged in, regardless of https being in the picture.
As for performance, I've played around with benchmarks using Goad on a micro tier EC2 instance and never found an appreciable difference between http and https.