Can we even do this in the physical world yet? Yes I can own a plot of land and by virtue of that have an address using one of a number of namespaces; postcode, lat/longs or even "what 3 words" but this is still subject to the masters of the namespace, and even the physical place could be subject to a compulsory purchase order to kick me out if the authorities decided to build a new motorway through my house or such.

Your point about public/private keys is interesting but there's a difference between an identity and an address, I don't see keys solving the addressing/discovery issue