I have been running squid to cache content along with privoxy to remove lower quality content for years; however, as more and more sites use HTTPS, the amount I can effectively cache or filter is greatly reduced.
Having an extra service running consumes memory and introduces latency while not providing any added benefit.
Are there some other reasons to continue running squid and privoxy? I could bump SSL traffic to cache it, but I still won't be able to leverage privoxy to filter unless privoxy supported passing in SSL certificate and key.