>Apple is not preventing you from choosing to buy an Android phone.
They're preventing you from buying iOS apps from anyone but Apple.
>Owning an iPhone is like being in a Walmart. You can either buy from the store or go somewhere else.
It's not and you can't. There's nothing inherent that forces you to only buy software from Apple because you own an Apple device. And you can't go somewhere else to buy your software because Apple blocks that.