I don't really understand all of what Facebook collects, and I kind of wonder if anyone does, BUT, I will say that their feature allowing you to download all of your data and also their ad settings are very extensive to see what ads are served to you and why they are served to you and what information Facebook thinks it knows about you and where it gets that information from.
On the other hand, I did a data collection request from Apple, and it was a VERY funky process compared to Facebook. I got an e-mail someone who took months to write back from their Ireland campus, and they just send a plaintext document back with my iTunes user account name, saying that was all the information Apple had on me.
Well, of course that isn't the case. AppleCare cases are saved for many years. All Apple products are registered to your Apple ID, which I gave them.
Similarly with Google, I've been able to easily see all my data stored with them across services in one spot on the web. It's very coherent. Easy to manage, easy to download. Easy to erase My data with Apple feels much more "trapped" and hard to manage.
I don't think Apple could do advertising if they wanted to. They just seem really bad at those types of services. They're kind of clunky in that often Internet services upgrades requires OS upgrades. I just don't think they're great at whatever that field of tech is called. In fact, they did have iAds for iOS which they abandoned.
I do think this is self-serving. I think data collection and processing it in useful ways is an area Apple has a huge weakness in (even local data like contacts in my address book Siri will often get wrong or their spell check won't recognize names from my local contacts, etc.**) and they try to turn it into a strength by saying it's about privacy.
Also as an aside, when I did Apple Sales Chat, there was very little concern for privacy. Apple Sales Chat is when you're on the apple.com site and a bubble pops up asking if you want help. I was on the other side of that bubble. Make no mistake, this was a sales job. We were told: They are reaching out to you, that means they want to buy, so if you lose this sale you did something wrong. I don't know how it worked, and this was about ten years ago, but once I chatted with someone, I could see a live view of whichever web page they were on within the Apple Store Online. It wasn't like screen sharing, it was like URL following, but it showed up on my end so that I saw the page they were on live. At that time, we also built carts for customers (which is a practice that ended not long before I left that gig). Anyhow, if a customer searched for an item in the store, we saw it. We saw anything they did within the store. If we sent them a link (which we often did), we would see if they followed it or not. So if we sent a link to an accessory and they didn't follow the link, we'd say something like, "Did that link work for you? Here let me try sending it again." But here is the really creepy thing: To make sure we got credit for the sale (it was supposed to link you to the customer to show sale conversion but it didn't always work), we had to give the web order number in the group chat to our supervisor. To do this, we stayed with the customer whether they were still chatting with us or not through the checkout process. I couldn't see their credit card number, etc., but I could see their address and so forth. And we even had a tag line we used which was a ruse (and I can't remember the exact wording), but it was something like keep the chat open so I can double check that we received your order (something like that). It was more likely to keep our chat linked to the sale if they kept the chat open. So after they checked out I would copy and paste the web order number from the confirmation page into our internal group chat. The whole thing about confirming the order went through was BS. There was no confirming it went through. It was just a ruse so we could copy the web order number.
So much for privacy. This was through Arise BTW, but we used all the same Apple internal tools that Apple used, and we were trained by Apple.
**For example, I'll say "Call John." And Siri will say, "I don't see anyone named John in your contacts." and then I'll say, "Call John Smith." And Siri will then get it. Well the name John is in John Smith, so . . . ? Or I'll write out a name and Apple will autocorrect it to something else, even though it should be smart enough to know that a name in my contacts is spelled intentionally.