I'm not sure I agree that you couldn't become informed about a single one. I think one is probably reasonable.
Presumably, if your service was important enough to the user and the third party tracking integration important enough to you that you're willing to ask the user to spend a few hours reviewing their 'contract' with the third party, then such a thing could be done. I imagine a lot of people would click the “I’m not reading all that” button though.
You could even envision a simplified sort of 'tracking declaration' as is done with (for example) insurance products here in Australia, where a sort of statutory precis gives the reader a good, bullet-pointed outline of the policy
I would wager that with a well formatted precis like that, it may even be possible to consent to as many as half a dozen 3rd parties. I doubt many people would though, if it was spelled out that blatantly and clearly what it's all about.
And isn't that the point? Hide what's really happening in so many walls of text nobody could ever conceivably bother with them?
So I think the person filing this suit is correct. The behaviour on show here is an end-run around even the idea of informed consent, and needs to be squashed.
(Edit - instead of all these cold GDPR compliance boxes and walls of text, sites should be honest: letting advertisers track you is how we make money, please click yes and we can get paid for your visit”, but of course it’s much more effective just to confuse people into ignorant acquiescence, or try to get people riled up about “stupid gdpr compliance nonsense”)