The worst offenders were typically politically slanted (as would be expected in any human run system or ideological subject) but not only that as many academic subjects are full of internal debates with varying priorities depending on context, which made me question the utility of relying on 'trusted' 3rd-parties like Snopes for fact-checking.

If the fact-checking sources are as editorialized or based on the author's worldview on what is 'true' then it's just as bad as the root source. What then is the point?

The utility is that they offer a bit of extended research on specific claims, which larger articles or speeches often can't go into for the sake of brevity, lack of research, or occasionally (and likely less so) intentional deception. Their utility should not be fact-checking in any absolute terms.

4chan has had useful research on a number of occasions, that have gone beyond other journalistic sources, but more often the motivation is not the truth but entertainment and like any open forum has it's share of conspiracies. It should neither be entirely dismissed or given some inherent 'authoritative' credibility. This is why context matters, a context currently beyond the scope of machines, and too dangerous for a few 'trusted' humans. There's no absolute authorities on a general internet-wide scale.