Post addresses should go away. "You're at home" or "you are away" displayed on your smartphone lock screen should do. For the rest, there's Uber. – I'm not so sure that this is how real life works. Understanding addresses (post or electronic) is an important part of liability and a sound mind. Also, how do you identify authority, if you do not know about uniforms or IDs?
a) you're confusing addressing something with presenting the address; b) you're completely (possibly intentionally) ignoring the context, which is all about specifically "www" part, the trivial non informative part that is just a historical artifact.
If in doubt about the historical context of the "www" subdomains: This was, when dedicated services were run on dedicated machines (or rather, dedicated network interfaces). "www" was just a default appellation (much like a well known address on particular services) for a server running W3 services. I don't see, why there isn't a use case for dedicated service domains anymore. (Not everything is WWW.) There's no magic to this and has never been. (The magic is in the port number as encoded in the protocol portion of a URI.)
Regarding the context of the example, all this is about navigating and about communicating how to navigate. Real live addresses tend to be much more messy, but they are bearable and users have been able to operate them for what is now several centuries.
