Earlier quoted context omitted.
Critically, if I want to use a smartwatch with an iPhone, I’m not limited to the Apple Watch.
But the analogy here is that if you buy Apple Watch, it is reasonable that it is tied tk iPhone. just like you are buying oculus quest knowing that it is tied to FB
You can also use both without an Apple account.
As an analogy, this is like Geico insurance requiring you to sign up for a United MileagePlus account because Berkshire Hathway owns both (hypothetically).