I might be completely wrong, but I doubt that OpenAI can sell enough ad space to cover their cost. Maybe their clicks will be more valuable and that will help.
Still I see this as a pretty desperate act. Google and Meta also makes their living of ads, but they've cranked that nob so hard, to please the shareholders, that their product is now suffering. If OpenAI does the same, they could easily crash as fast as they've grown. Complete boom and bust cycle in less than a decade.
I think they're going to try to charge a premium for ads because of all the context and personalized knowledge they have, but I don't think they actually have any more relevant information than Google in practice.