For a more meatspace example let's say you own a car with full self-driving capabilities. Now, the manufacturer of that car also runs a chain of grocery stores. It would be problematic if the car refused to drive too a different store. "If you've already to decided to buy a Walmart car then Walmart is the only store that you can go to."

At a certain point in debates like this everyone ends up over-examining analogies to a point where it isn't useful. To be a useful parallel you'd need a world where you can only buy two types of car and each one only lets you go to one type of shopping mall, or something like that. My point is, that isn't how either the real world works or how smartphone app stores work, so it's a debate over nothing.

There are two options, and one of them is provided free of charge by the world's largest advertising company.

The state of the smartphone OS market is so wildly different from the general-merchandise retail market as to render any comparisons meaningless.

So you can compare this to if you could only buy things at two different stores, each store has a hefty membership fee, and you were effectively locked into your decision for at least a year at a time.

"the definition of world is too narrow" is a pretty weak argument.