It's Chromium-based, so I don't understand how it could be "configured in the same way".

Could you please provide and example or two? I wish to verify it, since I didn't notice any last time I checked the site.

Sure, let's look at the page for Firefox. They claim that there are "Automatic connections to some websites you've visited, including their trackers" with the new tab page, and that they "couldn't find a way to disable it." Whoever made this website couldn't take 2 seconds to go to about:preferences and see the option to display recently visited sites?

They also have a section titled "Firefox tracks users with Google Analytics", which they're very misleading about. Instead of explaining that GA is only present in about:addons and that it can easily be disabled, they're extremely vague about it and just blindly say it "sends analytics to Google", which would lead people to believe its much worse than it actually is (i.e. Chrome level). There's an important distinction between: "Google Analytics is present on 1 page in the browser and can be disabled" vs. vaguely stating "Firefox send analytics to Google" without full info or context. Hopefully I'm explaining that well enough.

Its also disingenuous to consider Firefox's Captive Portal as "phoning home" without, again, providing full info or context. It has a legitimate purpose, to allow users to connect to public networks, and can be disabled for those who wish to do so. It doesn't give any data to Mozilla, all it does is detect if a captive portal is present. I think this is another instance of the context being important to have, which the website just simply doesn't give.

Another instance, look at their page on Tor Browser, where they just flat out lie and accuse Tor Browser of "sending telemetry".

I could go through more, but these are a few I notice immediately that I take issue with.

They're very clear that this is their approach (bold text on the home page). Even if you disagree with their definition, that doesn't make the site bad.

Categorizing something as spyware solely based on the number of connections it makes is horribly irresponsible at best and dangerous at worst. Whoever made this couldn't even be bothered to find what data is actually being exchanged for most of these connections. There's a lot more to determine how privacy invasive something is then just sitting and counting the number of connections it makes, and treating them all as malicious and for "tracking".

And there are many valid situations where a threat model should be this strict, consider anti-government activists in any country.

That's why this website is so dangerous. Calling Tor Browser spyware and saying it sends telemetry could trick people who don't know better to use worse alternatives. This even moreso extends to casual users too, who could also be misled into using a less private browser as a result of this website's insane claims.

It says "Not Spyware". https://spyware.neocities.org/articles/tor

They have a separate article up calling it spyware as well, see here. Weird contradiction from them and just shows this site isn't very well designed or thought out.