You do have to consent, but there are many parts where they don't let you say no and continue using, while all third parties are forced to make you say no and to continue using.

Apple is doing the classic "we don't share with third parties, we just collect a shit ton of data from everywhere and then make people buy our data indirectly via our ad sale services" like google and facebook do today. So it's not shared with third parties, but because of their scale it might as well be in effect size .

> I'm not familiar -- do you have to actively consent to Apple's tracking too?

It's called App Tracking Transparency and there is a scary prompt when Facebook/others do it. It's called Personalization and a friendly prompt when Apple does it.

These two are not the same thing. Every app is allowed to serve you personalized ads, without asking. ATT is about cross app/site tracking between other companies, which is something Apple has never done.