I think it's unfair to compare Facebook actively screwing us to Apple not adopting your proposed metric on their product and passively allowing a very popular app in their app store. Not a huge fan of Apple, but they aren't Facebook.
Apple does not have a tracking pixel on half the popular web. Apple's main source of income is through luxury hardware and subscription services. Facebook sells your information and attention to willing buyers.
So tracking might not be their business but they can very easily start a big business.