Google sells hardware and Apple sells ads, in great quantity in both cases. Not sure "it's that simple" at all.
Both Google and Apple control enormous number of devices, the data on them (or data collected by them), their software, and their users. They make money by selling you tiny bit of access to that, directly or indirectly. End of story. Should I remind you how much being special to privacy restrictions costs Facebook?
Google is something like 75% ad revenue, <5% hardware.
Apple is something like 75% hardware, <5% ad revenue.