This argument keeps on popping up, but I don't really understand why. Apple themselves already have a platform that's had a reputation of reliability and "just

This argument keeps on popping up, but I don't really understand why. Apple themselves already have a platform that's had a reputation of reliability and "just works" that is not a walled garden in most of the ways the digital markets act intends to prevent: the Mac. There's no evidence the the qualities of Apple products are strongly linked with them being walled gardens. Your iPhone will be fine. (Macs may not be as "just works" as iPhones, sure. I've personally seen that too many times. But computers are also intended to be more flexible and complicated in operation than smartphones, and regardless of personal anecdotes Apple is still widely regarded as building the most "just works" general purpose computers. And whatever faults Macs have, you'd be hard pressed to argue that if only the Mac was more of a walled garden that things would be better.)