For sure, it's just hard to tell them apart from a technical point of view. Tracking Preference Expression (DNT) [0] does make it possible with a Tracking Status Resource's same-party property [1], but it seems like almost nobody uses (or talks about) this. Medium.com is the only major site where I've seen it implemented: https://medium.com/.well-known/dnt/
Hey, I'm the main author of this. Happy to see that people like it!
As I wrote elsewhere in the comments we're planning to redesign the results page and rewrite all the text later this year. The current page hasn't changed much since mid-2016. Need to refresh/expand technical advice, be more clear about the limitations of the service, etc. I'll note down all suggestions here.
I'd also like recommend a similar project that was inspired by Webbkoll: https://privacyscore.org/ -- it's slower, but also integrates things like testssl.sh, and most importantly lets you make lists of URLs to check. It uses OpenWPM [0] which has been used for many interesting studies,[1] such as "Online Tracking: A 1-million-site Measurement and Analysis".[2] (Webbkoll uses Phoenix+Puppeteer)
Great tool. But if you'd have a list of top 10 checked sites at the top, say by sum of all three counters, it could actually bring some action, no one would like to be in this shame list.
Just a historical note that I found interesting - it was in fact obvious (to some) already 22 years ago. From RFC 1945 (HTTP/1.0), May 1996, 10.13 Referer [sic]:
"Note: Because the source of a link may be private information or may reveal an otherwise private information source, it is strongly recommended that the user be able to select whether or not the Referer field is sent. For example, a browser client could have a toggle switch for browsing openly/anonymously, which would respectively enable/disable the sending of Referer and From information."
This recommendation was not followed in any meaningful way, but Referrer Policy (https://www.w3.org/TR/referrer-policy/), which supports a whole bunch of different policies and is very easy to implement (and now widely supported), at least makes things slightly better.
Gopher pretty much died long before Google was a thing. Here's a good article: https://www.minnpost.com/business/2016/08/rise-and-fall-goph... (lots of interesting comments below the article from many of the people involved)