That would be true, if Apple couldn't literally write any TOS they want that allows other App stores or billing methods and then add "but you can't include tracking that invades our users privacy or resell their data".
That's just as enforceable on their end, and not anti-competitive, assuming Apple themselves don't launch their own ad platform and tracking...
Who else is going to care about privacy though?
For the payment situation for example, Apple Pay (and Google Pay) use EMV Tokenization so that your actual credit card number is obfuscated:
* https://en.wikipedia.org/wiki/Apple_Pay#Technology
* https://en.wikipedia.org/wiki/Google_Pay_(payment_method)#Te...
Credit card numbers are used by retailers to data mine their customers:
* https://www.forbes.com/sites/kashmirhill/2012/02/16/how-targ...
As does Samsung Pay. As could any number of tap to pay providers, if Apple would let them on iOS.
Here’s another example: Facebook knows exactly the 100 people they show my ads but not giving me their full name, relationship status, list of friends, their gender, sexual orientation, etc.
But does Apple have access to things? Or do they (sometimes?) design things so that even they don't have the information?
A lot of the time they do things 'on device'.
My general worry is that the entire discussion is shifting “from what’s good for the customer to this other company cannot do something shady because you protect the customer”.
Does Apple enjoy this gatekeeping practice? Of course they do, but so does Google with Android and they abuse the crap out of it.