That's not a fair comparison. A desktop wallpaper could be 8 MB for a modern OS just because of screen resolution. A 4-minute music video would probably be 100 MB.
It's still useful for comprehending the scale of volume. The useful part of the article is a few KB.
But PC gamer isn't downloading 8mb wallpapers or 100mb 4k music videos. They're downloading ads and and other nonsense.
Plus, if I decide to download a music video, that's on me. I chose to download a 100mb file.
If I just want to read what amounts to a few paragraphs of text with some branding, I don't think it's fair to say that I'm also choosing to download 40+mb of nonsense that isn't text. Maybe in this new modern web, that is a conscious decision I make by clicking on any link anywhere, but I think the point of the article is that it shouldn't be the case.