The Google ad exchange favored its own platforms, limiting the ability of other exchanges to compete fairly in bidding for ad inventory. https://www.justice.gov/archives/opa/pr/justice-department-s...
In limiting the number of bidders, Google inflated the prices for ad inventory. https://www.abc.net.au/news/2024-11-26/closing-arguments-giv...
Google engaged in bid rigging where competitors agree on who will win a bid, again to inflate prices. https://www.justice.gov/atr/preventing-and-detecting-bid-rig...
Google entered market allocation agreements to create an unfair playing field. https://www.winston.com/en/insights-news/avoiding-antitrust-...
There's a case to be made that on top of google being broken up, the market should be heavily regulated in order to restore trust for market participants.