Yeah but now it's a personal identifier that actually moves with you when you move to a different physical address. In terms of privacy, that might just be worse.

How do you plan to order anything from an online shop without the shop knowing your delivery address?

You put a trusted intermediary (JP Post) that knows the address in the middle, and provide the seller with an identifier that the intermediary can associate with your physical address.

That’s already how it works if you buy something trough the online marketplaces here - Mercari et. al.

Mercari knows addresses of all counterparties, but the label that the seller puts on the package doesn’t have the destination address, and the label the package has when it reaches your door doesn’t have the seller’s address either.