Liquor stores are not candy stores, yet they are allowed to sell candy to minors while being prohibited from selling liquor. The principle is straightforward: regulation should follow the product, not the venue.

All pained analogies are both pained and invalid.

iOS is not a liquor store, and allowing people to use other payment processors or even other stores on the platform is not selling liquor to minors.

Note how your analogies immediately fall apart for other platforms like, for example, Apple's own MacOS.

You can ignore the analogy, just contend with my actual point: regulation should follow the product, not the venue. How does the analogy fall apart on macOS? The choice of some venues to be libre doesn't mandate other venues to be libre.

By game count and revenue, the App Store is very much a game store.

You may not think of the iPhone as a walled-garden gaming handheld with smartphone features, but that's basically what it is from a business perspective, and games are in fact the majority of apps on the system.

Epic (a game company) sued Apple to get it to charge lower platform fees than other game stores.