Google makes, quite literally, billions of dollars off the bottom of the barrel.
There is a dark iceberg under the consumer Internet. Online pharmacies. Rebill scams. "Government grant" applications. High interest loans. Educational institutions of dubious utility (disclaimer: took one's shilling once, indirectly, and regret it a bit). Spam, scams, and the like, on a massive scale.
There is a UI for AdSense publishers where some Google PM made the decision "If we give them options to tart up their website less, let's tell them how much money it costs."