> Does that mean the state actually owns it?
By registering the car and obtaining a license you are agreeing to obey the rules set out by the state in exchange for permission to use the roadways.
To steelman the argument, you could argue that by using an iDevice you are using Apple's services and agree to follow the rules set out by them. But there is no such possible way to use an iDevice without relying on Apple's services.
With a car you can have it delivered and only use it off public roads on your own property. That would be a lot less useful, but it is something people do sometimes, such as with vintage/museum cars, race cars, construction/farm/mining vehicles, etc.
It's always your vehicle. The issue is the roads not the vehicle. But with an iDevice, even if it's legally "your phone", it's been designed to be impossible to do whatever you want with it within the bounds of the law, which weakens the traditional notion of what it means to "own" something (ie "right of disposal").
Again to steelman it, the retort is "Apple has the right to manufacture devices in alignment with protecting their business model, if you don't like it then buy other devices". Which is fine normally, except that the only other major similar device manufacturer is starting to do similar kinds of things and our society increasingly depends on the assumption everyone has a phone.
So what's increasingly becoming the scenario is that you have a choice: either allow your rights over your own property be infringed, or allow your ability to participate in society be infringed.