Is it, though? I feel like calling Alphabet the main or the sole perpetrator would be like calling Al Qaeda the only terrorist group or the US -- the only democracy.

It is. We're talking about video platforms that shape content through algorithm, rather than human taste. This is only necessary when the amount of content is so vast that there is no moderation. This describes one platform and one platform only: Youtube.

What's described in this article is basically the malignancy of the algorithm. This is not a problem Facebook has because their videos are not only targeted and siloed, they aren't aimed at children. This is not a problem Vimeo has because their content is barely browseable. This is not a problem Netflix or Amazon have because their content is licensed and curated. It's only Youtube.

Google, for its part, revises its search algorithms regularly. They kill entire industries in the process. That something such as a "private blog network" can be profitable and lucrative (as opposed to paying for Google Adsense) says something about the primitive nature of their algorithms to begin with... but it also shows how keenly interested Google is in refining things when it affects their profits.

Youtube is not profitable. It probably never will be. Alphabet's approach with Youtube is to make sure it's the only channel anyone ever thinks about uploading content to, and when they start paying you back they're cosa nostra secretive about the terms. You basically need a million hits before they'll give you a dime... which means all the videos shown aren't, really. What we're observing is an algorithmic shotgun blast in an attempt to wrest profit from an algorithm that says "if you see six seconds of it, even by accident, it counts as a view."

Alphabet could fix this by not being so awful. Nobody else is as awful as they are. It's an Alphabet problem.