Earlier quoted context omitted.
It's right in Apple's privacy policy, see Disclosure to Third Parties section: https://www.apple.com/legal/privacy/en-ww/ They obviously sell user data in aggregate - not at a personal level, but which of the big tech companies sell personal data (maybe FB / Cambridge Analytica?) Also, Apple has Google as the default search engine which Google pays billions for. Is that selling your personal data?
You mean the disclosure to third parties section that explicitly says "Apple does not sell personal information"? I can't see anything in that section that says that they sell information to third parties, personally identifiable or aggregate (I would consider the latter to be "personal" data as well fwiw). Is there a specific sentence you're thinking of? It seems to be talking about the necessary sharing of data tha…
"Ads that are delivered by Apple’s advertising platform may appear in Apple News and in the App Store. If you do not wish to receive ads targeted to your interests from Apple's advertising platform, you can choose to enable Limit Ad Tracking, which will opt your Apple ID out of receiving such ads regardless of what device you are using. If you enable Limit Ad Tracking on your mobile device, third-party apps cannot use the Advertising Identifier, a non-personal device identifier, to serve you targeted ads. You may still see ads in the App Store or News based on context like your search query or the channel you are reading. In third-party apps, you may see ads based on other information."