Chris, you're spot on in your statement about (in most cases) senseless encryption and artificially created requirements - quite often coming from the same party that wants us to believe they're advocating "sustainability" (a much hollowed-out term these days).
Take Wikipedia for example. It's a website that serves strings of text and pictures from their server to a user's client. That's so basic web 1.0. It's beyond me why they can't offer an unencrypted access via http, despite numerous people who had asked them about it in the past. After all, Wikipedia complains they want to be that open-to-everybody worldwide encylopedia (but then they hide behind encryption!?)
The problem I see with a kind of public proxy service is the same that I see with the big corp internet of today - you have ONE person that basically controls the traffic and you, the end users, don't really know what they're doing. That goes both ways, btw - how do you know what your users will use the service for ? That's a tricky thing so I would only offer such a service to folks I'm 100% sure they won't do silly things. So rather than centralization, decentralization is the way to go in terms of proxies. Jubadub provided some good links in his post, check them out.
Finally, as somebody who has been using a proxy in conjunction with Classilla for years I can say that it doesn't really solve the problem. Yes, you can reach more websites. But with ever more sites relying on JavaScript to even render correctly (who cares about "progressive enhancement" these days?) you won't be getting far.
The solution as I see it is rather to create an alternative WWW with low tech websites - a web within the web, so to say.
That why I created my projects. And after some digging and searching I found there are hundreds of cool projects - created and maintained by individuals (not corporations). It's just that ever since Google focussed on brands, these will never pop up in Google's search results again and hence go unnoticed. But they exist! It's not that the so-called "fan page" came out of fashion, it's rather that Google & others killed it off because it didn't bring any ad revenue in!
So the real challenge is really finding the unencrypted low-tech websites. I use
Wiby.org a lot for that, as it focusses on live websites (not incomplete Internet Archive snapshots from the past). I've fed it two dozens or more URLs already. I'd wish more people would do that.