They have a numeric scale as well, which scores fox at 6.1 and the guardian at 5.7 (I think, I looked yesterday)

The guardian’s editorial is politically biased, it wears that on its sleeve, their opinion pieces come from a moderate-left viewpoint. But its reporting is generally factual, even if they make mistakes sometimes, as reported on that site.

Whereas they literally label some fox links as “PANTS ON FIRE”, I.e deliberate falsehoods. And we all know the story around, say, Dominion, where Fox knew they were lying but carried on. And the site gives them a higher score?

This is enough for me to doubt the site is anywhere near a reliable comparator.