Then you probably need to watch it again. At 3:26 he states “if a power cord really made a difference it would be something you could measure” which he follows up on at 4:05 where he shows the data from a particular cable comparison and states that none of the other exotic cables he’s measured made any difference to distortion or noise floor etc. I know @Graeme_Finlayson has already mentioned this, but I think it bears repeating - this video is about as objective as you can get. Testing → no empirical difference → objective and rational conclusion.
Sounds pretty conclusive to me.
See above.
Rewatch 8:10 to 9:15 where he discusses why reliable listening tests are highly problematic with respect to power cables. If that doesn’t convince you, do some research on auditory memory.
To reiterate my previous point: I don’t see this video as any sort of example of cognitive bias, let alone a “classic case”, so please feel free to have another go at explaining or justifying your claim. By the way, I’m perfectly happy for you to say that you dislike the video, or that you disagree with everything he says, but I don’t think that constitutes any sort of justification for making claims that are patently and egregiously false.