"local monopoly": meaningless. That's like saying that Gmail has a "local monopoly" on web-based email because switching would be a hassle.

many people still considered windows a monopoly, when you could easily buy redhat at most local stores. MS Office file formats were also considered a monopoly by Richard Stallman, because businesses used them and it was difficult to now change (there are tons of competing formats).

the tech industry likes to change definitions to fit their viewpoints.

What people think is a monopoly and the legal definition of a monopoly is different. You have to be able to show harm to e consumer, something's hat is going to be challenging to show with a handful of hidden APIs. APIs, it should be noted, that somebody could implement themselves (at least for the sample given; whether it would be approved is, of course, questionable).

On the other hand, it could be used as evidence of part of a larger anti-trust case, but given that Android devices are cheaper, perform just as well, and have a strong ecosystem, that's going to be hard to pull off.

'Local monopoly' is meaningless. Every single business has a local monopoly on supplying services under the contracts they've made with their customers. And yes, Apple's total control of iOS is very much part of the contract when buying an iPhone.

When deciding if a monopoly exists, the relevant threshold is whether the customer had other reasonable options at the time of entering the contract, and in the smartphone world they unequivocally did have other options.

iOS users do switch to Android. You don't see it all the time because users (in the US at least) are stuck in 2 year contracts and phones are an expensive purchase. But they do.

Does Honda have a "local monopoly" on sedans because Civic drivers don't usually switch to a Kia Forte overnight?

Not quite, because "sedans" is not the relevant market. It isn't that you can't buy a Kia the next time you go to buy a car, it's that once you own a Civic you have to put Civic replacement parts on it. So then you get the relevant question, does Honda have a monopoly on any Civic replacements parts? Some parts (e.g. brake pads) may be produced by third parties in competition with Honda, so for those parts the answer is no. For other Civic parts not made by anyone else, the answer is yes.

So to get back to Apple: They don't have a monopoly on smartphones, they have a monopoly on iOS app stores.