Right. I didn't mean to imply that they would infer the correct address to send it (although I'm sure that's a service you can pay extra for). It's useful for sending mail to people in rural areas whose home has no delivery route (what we called in more innocent days "a mailman"). Or, indeed, to those with no fixed address.
Whether mail is delivered to a person or just a numbered box is one of the reasons for specific services that verify receipt, such as Registered Mail, Certified Mail, and Restricted Delivery. As this thread shows, it may seem more convenient to click a form saying "don't require my signature", but then you have given up one of the service guarantees that you paid for.