Earlier quoted context omitted.
If you've chosen to buy something from Apple, it's hard for Apple not to know that you've bought it. I don't think that's an issue. What is an issue is the cross-correlation of any given company's data on you with lots of other "big data" companies, building a profile, not just of what you've bought from X, but from Y, Z, hell throw in the whole alphabet, why not ? Then there's the machine learning that says when X,Y…
As far as I read the support doc, it seems like if say I purchase an ebook from a third party App, should Apple have this data because they mandated the forced use of their payment system. (I don't like user profiles based on purchase data from their store itself as well) In this example, Apple is not just the store but also your payment processor(a forced one at that). So, they know about which cuts of meat you like…
Their processes and org structure is not built for that either with siloed teams. So much that quite often some teams will not know what kind of data is being collected by other teams even.