You are still not looking at the definition of"domain name" in my context: the ownership context. I totally agree with you on the technical side, in most technical context a root-level domain or subdomain is largely the same thing.
In the ownership context the definition differs. Please if you want to challenge my notion of "subdomain" please only challenge this definition only. You don't own a subdomain as strongly as owning a root-level domain, because in the first case the only attestation is on the database of obl.ong/github.io/etc while in second case your ownership is attested by the ICANN registry, which is how things has been working for the past 20/30 years.
In the ownership context the definition differs. Please if you want to challenge my notion of "subdomain" please only challenge this definition only. You don't own a subdomain as strongly as owning a root-level domain, because in the first case the only attestation is on the database of obl.ong/github.io/etc while in second case your ownership is attested by the ICANN registry, which is how things has been working for the past 20/30 years.