Every time I’ve moved, for months afterwards I keep having to fix my address when using Apple Pay or setting directions to home, etc. because it seems like they keep multiple copies of that information all over the place, instead of referring to a single piece of information.
Places I can think of where I’ve had to update my address one by one: each credit card I have associated with Apple Pay; Maps; my own contact that I can share with others; subscription information; shipping address for Apple Pay.
I get it that some people use separate billing and shipping addresses, but for the vast majority of people the use case is “I have a single home address where I want to direct Maps to, be billed at, and ship stuff to, please update it all at once when I update my address.”