My aside wasn't intended to be pedantic, rather observing the apparent inconsistency in how it appears people think about these matters versus what the present situation illustrates the reality to be.

> but (1) I’m referring to a registrar/issuer, which makes it yet more complicated

We're also talking about a ccTLD which makes it even more complicated. AFAIK those fall entirely under the jurisdiction of the respective UN recognized government although I don't know how strong that agreement is in practice (treaty versus something else).

So at that point I guess we've roughly got ICANN -> US federal government -> CA state government -> registrar -> private party -> sublet.

The way it worked is that someone nominally representing the CA State Government had* ca.us, and they in turn gave* san-jose to someone who nominally represented San Jose, los-angeles to someone who nominally represented Los Angeles, santa-cruz to someone who nominally represented Santa Cruz, and so on. city-name.ca.us domains were still free (and charging for .com and .org domains was a new thing at the time); you would look in the zone file to see who owned* a given domain, email them with your nameserver names and IP, and they would add it to their zone.

This isn’t how things are done these days; names visible to the public are pretty much always in the form {domain}.{tld} or sometimes {name}.{domain}.{tld} (e.g. my own https://samboy.github.io). Registration is now done by bots and companies that spam you to death to try and get more money from you (the Internet wasn’t like that in the beach.santa-cruz.ca.us days). Domain names with multiple levels of delegation aren’t around they way they used to be.

* rented/leased/had control over/whatever