[acdha]

I think that's a question of whether you're thinking of “unavoidable” in the technical or social context. You could design a system where anyone can run their own root but would you want to operate a business in a world where your advertisements need to list which of the DNS roots you use and spend time paying to register with everything which becomes popular enough that spammers would consider registering your names? That seems even worse than the proliferation of top-level domains since there at least the name which people see is actually different than the one you advertise.