He's not saying advertisers don't compete. He's saying it changes from advertising being a massive risk as well as a cost, to just a cost. So the auction is won

He's not saying advertisers don't compete. He's saying it changes from advertising being a massive risk as well as a cost, to just a cost. So the auction is won by the company with the biggest instantaneous profit margin on a SKU, instead of the one with the biggest war chest that can afford to risk on that massive prime time slot. This change in incentive favours shitty products.