[toast0]

Domain names are primarily useful because of the global consensus about how to resolve a name.

Building, and maybe even running an alternative root is simple from a technical basis, but without global consensus, it's not very useful. Alternic was around for many years and didn't get anywhere near enough adoption to be useful.

If the concern is cost, some TLDs offer domains for much lower cost, some even free. There are many domain owners that offer subdomains for free too. If you have a domain for $10/year and let 1000 people have a subdomain, it's not worth billing them, etc. There's certainly a discussion available about the costs being unjustifyably high, but they're not that high in absolute terms, and lower prices would seem to encourage more hoarding.