So -
1) HUB 3 weeks ago extensively tests B580 and publishes video - "Intel saves PC gaming?" (248k views) Gives thumbs up, smiley face.
2) HUB 2 days ago in new video - "Intel ARC big problem!" (172k views, followup video - 129k views) - sad, frowny face
3) ???
I think it is primarily because ARC does not conform to industry norms. Usually you test the card with the fastest gaming CPU to eliminate any bottlenecking, as they did initially, and tell viewers you don't need a CPU nearly so powerful to get full performance. That in fact, you can pair it with a much more affordable CPU, because the card will be the bottleneck limiting performance the vast majority of the time.
HUB did do the overhead testing a few years back that revealed Nvidia was a poor choice compared to AMD for old systems, due to it. Few listened, fewer remember, and they bought Nvidia anyways. Combine it with the lack of Nvidia game optimizations for older generations, and you have AMD fine wine.
I was going to rant about Steve not including the RX 7600 in the charts, because it makes it look like he doesn't want Nvidia to get exposed too. He did mention Nvidia's issues at the end of the last vid, but downplayed its significance. He also is rushing the content out so I don't want to jump the gun. He said more is coming this week, and he'd better have AMD in those charts using a Ryzen 2600 so we can see for ourselves the 4060 is not limiting performance substantially more than AMD does.