> The same is done by restaurants for things like Uber Eat/Postmate: they have their prices on their menu, and a marked-up price on these platforms
I do not believe Apple's tax for IAP applies for physical goods or services. Only digital products or goods. If those companies are charging more, it might be for another reason.
> 3.1.5 Physical Goods and Services Outside of the App: If your app enables people to purchase goods or services that will be consumed outside of the app, you must use purchase methods other than in-app purchase to collect those payments, such as Apple Pay or traditional credit card entry. Apps may facilitate transmission of approved virtual currencies (e.g. Bitcoin, DogeCoin) provided that they do so in compliance with all state and federal laws for the territories in which the app functions.
> but couldn't they markup the In-App-Subscription by whatever % of cut Apple is taking?
They can do this but they are not allowed to inform their customers on the iOS app that the prices are lower elsewhere
> Section 3.1.3(b) Multiplatform Services:
Apps that operate across multiple platforms may allow users to access content, subscriptions, or features they have acquired elsewhere, including consumable items in multi-platform games, provided those items are also available as in-app purchases within the app. You must not directly or indirectly target iOS users to use a purchasing method other than in-app purchase, and your general communications about other purchasing methods must not discourage use of in-app purchase.