I'll second the question: Can you give examples of poor fact checking.
I have seen very biased fact checkers - their information is accurate, but their selection of things to factcheck were highly partisan.
But I've also seen fantastic fact checkers.
So some judgment is still needed. But on the whole, I wouldn't put fact checkers down. The good ones are far better than any news site I've been to.
I would say that. In fact, I trust them even less than the outlets they cover. Most "fact checking" is opinion disguised as analysis making it just a boring op-ed.