If this is true, 2 of the 3 parties here are motivated to bypass Google to increase the money publishers earn and how much advertisers play, are they not? If's not that hard to set up an ad server from scratch. The issue of course is inventory.
But publishers and use multiple ad servers. In fact there are tools for them to pick whichever impression will pay them the most from those available. Advertisers are free to buy on multiple platforms. At least I see no allegation that Google is actually or effectively restricting the use of other tools.
So can't Google use this to say that publishers use them because they pay the most? And advertisers use them because the ads are the most effective? Advertisers in particularly are heavily metrics-focused. In the background, they're analyzing ad performance (in terms of impressions -> clicks -> action) based on audience segmentation.
Now the DoubleClick cookie does have value because it's so widely deployed, Google has a lot of information to derive behavioural characteristics about the user. Just based on what sites you go to, Google builds a profile of your interests, your likely (implied) demographics and so on. You can argue that this cookie is anticompetitive.
But I don't see "cookie" mentioned once in this article.
So I'm really not sure where this goes. It could be the reporting just isn't great on the case because it requires some legal knowledge. I guess we'll see.