I'm not sure quid pro quo even matters. A search engine is more like providing a taxi service. You're just taking people to a place.

Now the AI summaries are a different story. One where there is no quid pro quo either. It's different when that taxi service will also offer the same service as that business. It's VERY different when that taxi service will walk into that business, take their services free of charge[0], and then transfer that to the taxi customer.

[0] Scraping isn't going to offer ad revenues

[Side note] In our analogy the little text below the link it more like the taxi service offering some advertising or some description of the business. Bit more gray here but I think the quid pro quo phrase applies here. Taxi does this to help customer find the right place to go, providing the business more customers. But the taxi isn't (usually) replacing the service itself.