Maybe the App Store’s ads (e.g. when you search).
"Ads that are delivered by Apple’s advertising platform may appear on the App Store, Apple News, and Stocks. Apple’s advertising platform does not track you, meaning that it does not link user or device data collected from our apps with user or device data collected from third parties for targeted advertising or advertising measurement purposes, and does not share user or device data with data brokers."
Despite how much you might trust Apple, you can agree that they should have to have the same tracking restrictions that all other apps have.
This seems pretty straightforward.
It wouldn’t be fine if Apple sold that data to third parties.
This seems to be what most people expect. My mom knows that what she’s doing on Facebook is tracked by Facebook. She probably does not know that what she’s doing in other apps is also tracked by Facebook.