It's very real scarcity. We're talking about a single unified globally unique namespace, that must serve billions of potential registrants. There are only so many short strings and common dictionary words available, and way more people want them than can get them. So a domain like e.g. clothing.com, or clothing.{some other popular TLD} is absolutely a very scarce economic good in a real sense. It's more scarce than almost anything else I can think of; most products are fungible and more can be manufactured to meet increased demand, but you can't sell multiple copies of the same domain name. A good domain name is like an original artwork by a known artist, in scarcity and in price.