This is the problem with "fact checkers" on cable news, snopes, etc., and exactly why the new censorship push by Google, Facebook, et al is alarming: They pick and choose how to interpret the story according to their bias. They put a huge TRUE here, when this is false and they even admit its false: "Whether it's true that Lessig has 20 electors on board is impossible to verify unless they make themselves public. So far, only one Republican elector has publicly stated he will not vote for Trump — Chris Suprun of Texas." These fact check organizations take things literally when it suits them, and play loose with the facts when it doesn't. They are saying the CLAIM is true, not the substance. This is fake news designed to change minds by headline.
As far as I can see, the problem is just that their UI does not have a "We don't know" state. In the article, it says that they can't tell if the story is true, followed by a "but". The "but" seems to be enough to rather label this as "true" rather than "false", even though "we don't know" would be 100x more appropriate.
Is fact-checking in any sense worthwhile?
In my opinion, no. Choose who you trust, and if you find out they've deceived you, don't trust them any more.