> For a lot of web pages this is true, but what about sites like restaurant webpages? They have very few actual pages on their site, and they don't change depending on who is making the request. If I request the site over HTTPS, anybody that is sniffing my traffic will know that I'm visiting that domain and thus can request the content themselves. The encryption here is not providing anything.

The value of encryption as a whole increases when everything is encrypted, because it is harder for an adversary to distinguish "important" traffic from "unimportant traffic". It may not matter for that domain alone, but it certainly matters in the bigger picture. It significantly increases adversary cost.

> If you are sending/receiving personalized data, e.g. logins, search requests, etc., then you should be encrypting the requests. You would still be encrypting huge amounts of data for no reason, the CSS and static images used on the site are not being transmitted with or based on any personalized data, so any sniffer will already know that these resources would have been downloaded by you anyway (and I don't care if an attacker sees the CSS of a page I'm looking at anyway). Requesting these static resources over plain HTTP, but authenticated via hashes or signatures, doesn't provide an attacker with any information they wouldn't already have.

False. Assets can leak very easily, disclosing what content you are looking at. Just identify which assets are not loaded on every page.

> And yet Tor is the only way to actually protect against sniffers tracking which domains you visit. If we really care about encrypting all the content - including non-personalized, static content - then I don't see why we wouldn't also care about protecting the domains we visit.

It's not. The exit node still sees your traffic - and this is also why routing everything over Tor is a terrible idea (and incidentally, the same reason devices like the Anonabox are fundamentally broken). If you tunnel personally identifying traffic along with "anonymous" traffic, you're "contaminating" the anonymous traffic with your identity.

> I totally agree with this. However I think I come to a different conclusion. [...]

Saying that TLS is "not entirely useless" is a very poor argument for not working on making it better.

The "different levels" you suggest are pretty much already implemented as such, except there is no "authenticate but don't encrypt" level, because it's not a useful or desirable level to have.