Cook has gone so far as to call for tighter regulations on explicit user data sales, so likely not much there. Maybe in its ad platform aggregated data might be used.

The closest thing in that regard I could find was their mention of advertising sales in their quarterly report. Likely user data in some aggregated form is sold to sellers, like FB does

Services Services net sales increased during the third quarter of 2020 compared to the third quarter of 2019 due primarily to higher net sales from the App Store, Video and Cloud Services. Year-over-year Services net sales increased during the first nine months of 2020 due primarily to higher net sales from the App Store, Advertising and AppleCare. Advertising net sales includes net sales from licensing arrangements and the Company’s advertising platforms.

Here is one snippet on their ad efforts (from an unlinkable ad cancer adweek site):

Apple Is Quietly Ramping Up Its Ad Game With Search Ads Expansion The App Store is trying again at one of its few failures

really sad read, weird digital form of Quigley’s decline of civilization stage where empire fears attack from outside threats.

Also, this is clown-world: “TikTok will either have to be sold to a US company such as Microsoft ...”