Well, I'd argue your model of usefulness and the concept of a public good is broken. We are living in the Internet and names are cheap. If for some historical

Well, I'd argue your model of usefulness and the concept of a public good is broken. We are living in the Internet and names are cheap. If for some historical reasons (I'd say, maybe even related to artificial scarcity), .com|.org|.net got more popular than they probably would, this is fine. gTLDS (generic top-level domains) are here now, and if they don't suffice, something else will eventually appear.