> so passionately about the reverence of `co.uk`

It's not reverence? I think that you're missing that it was a requirement. Basically every country (that followed ICANN's original rules) does this: .com.au, .co.nz, .co.jp, .com.mx, .co.ke (+ the org/net variants for each country)

The US is the only country where registering .com was allowed by ICANN (and not .com.us or something).

ICANN relaxed these rules in the 2010s I think, so now you can register 2LDs at most/all of those country TLDs.

Sovereignty? If you live in the UK, choosing a registry in the UK is a pretty good idea even if they only offered 3rd levels. You’ll have someone to contact and possibly sue locally. Your domain will be subject to UK law and standards, not those of a foreign registry.

> My point is both that it's hard to tell,

Its not hard to tell for things like ".uk" or other serious suffixes.

It only (maybe) becomes hard(er) to tell for all the vanity ccTLDs that came along in the 2000s. But even then 10 seconds on WHOIS and Google should fix any doubt.

> about the reverence of `co.uk`

What are you on about ? Lots of other countries do it too. Japan is one example given already here, but there are dozens. It is very common practice for country tlds.