Every time you open the App store, you're opening a giant garden of advertisements. These ads are extremely lucrative to Apple. Every time you update the OS, it prompts you with ads to sign up with more services. Every time you open Apple News, the same thing happens: you're bombarded with ads to sign up for a premium subscription. When I still had an Apple laptop, it would constantly give me a popup asking me to signup for iCloud, even though I hadn't consciously ever used it.
At nearly every turn, engaging with Apple software leads to profitable ads for Apple. (Usually in the form of direct subscriptions, or commission based advertising.)
What do ad companies love? User data! This is as true for Apple as it is for Google. The difference: Apple has an iron grip on their advertisements like no other company in the world. This gives them the tools that let them pretend they're not an ad company. They are.