Apple's fees are on digital goods, not physical ones. Amazon doesn't pay a fee for me to place a physical order in the Amazon app, nor does the laundry app in my old apartment building.

I thought parking counts as a service, not physical goods, but then again I think I paid parking via app in the past, with external payment gateway, so you're probably right.

The in-app purchase system is the one which takes a fee, and is only sometimes required (and only _usable_) for services or digital goods consumed in the app itself.

Any real world good or service would fall onto Apple Pay, which makes its money through a micro fee on the card issuer, basically to use the phone as a convenient, highly fraud-resistant card.