> The OS APIs that most apps use are already paid-for by the user when they buy the device.

That argument would assume no cost for upgrades.

I remember having to buy new operating systems.

That said, looking at the state of recent OS upgrades, I think I'd have been happy if the only changes over the last, oh, decade or so, had been purely security updates. But these too are not free.

> Apple wants to double-dip and charge developers for the value that the users already have by virtue of owning their iDevices with all the necessary iOS paraphernalia in them.

Yes, obviously they want to make as much money as possible, and this is at odds with consumer interests.

That said, I have the impression that for many users, the benefit is the app ecosystem, while for many developers the benefit is the users. Endless marketing cycles of new-shiny-API for one, and new-shiny-UI for the other.

That said, power-law distribution, so "the app ecosystem" is probably mostly Meta, Google, Amazon, as specific names, then becoming somewhat vague with "whatever work mandated of Slack or MS teams", "their bank", "three or four supermarkets", and "a taxi firm who may or may not be Uber".