That's clearly a very bad idea. Maybe .gov was supposed to be that initially? The USA have it for themselves alone. Thankfully other countries have their ccTLD and can reserve a subdomain for their government official websites, like .gouv.fr in France, because they can't have .fr.gov (which would look strange anyway, since "gov" is a shorthand for the english word).
And this is not the only instance. Initially, the .edu was for all education institutions, but at some point it was unilaterally decided that only higher education institutions in the USA should be authorized to use such domains, which is a shame. For institutions still using it outside the US because they registered it before this decision, a single mishaps like missing the renewal deadline and they won't ever be able to get their domain back. And .edu can only be renewed in the last two weeks before expiration (thankfully now it is possible to pay for three years at once rather than a single one but that's recent).
So, the history of US-centric management of the internet strongly suggest that it's a good idea that countries have and can control their own TLD. Even if a few people feel like their vanity domain name should use what happens to be a ccTLD.
> Maybe .gov was supposed to be that initially? The USA have it for themselves alone.
.gov dates to 1984, back when the internet was the ARPA-Internet. At the time the whole thing was a US military network that some research institutions were permitted to connect to. .edu was never intended to be used for every school in the world, just the institutions collaborating on US government research.
If you think about the history of the internet from today's international perspective, it sounds strange, because it never was that from the beginning. It always was a US military computer network that grew way beyond the initial intent. It wasn't until 2016 that the US government decided to hand over control to the international community.
> .edu was never intended to be used for every school in the world
There was a time when .edu domains were attributed upon simple requests as long as you were an education related institution, from wherever in the world. It only later became paid, and then restricted to US institutions in 2001 (that is 16 years after the creation of the .edu TLD, contrary to what you say). I know this because I inherited the management of such a domain for a French university directly from the person who created it back then and who told me the whole history of how they got hold of this domain name.
I insist on saying "institutions" and not "schools" because it's what I can see. Examples still in use in France includes polytechnique.edu [1] but also snes.edu, which is the website of the main workers union for middle and high school teachers in France (SNES-FSU).
Also, note that nothing in its text seems to limit the scope of the RFC 920, the one you linked, to the US.
Correct, .edu wasn't explicitly restricted to US institutions. But at that time, the entire ARPA-internet as a whole was only used by institutions that were doing something related to US government research. There wasn't really a thought to restrict domain usage for anyone, because the entire network was restricted access. The ARPA-internet wasn't open to the public, and things like websites and ISPs didn't exist. It was just a tool for researchers to use at work. The idea that .edu would ever accommodate a middle school teachers' union in France was not on anybody's radar.
And this is not the only instance. Initially, the .edu was for all education institutions, but at some point it was unilaterally decided that only higher education institutions in the USA should be authorized to use such domains, which is a shame. For institutions still using it outside the US because they registered it before this decision, a single mishaps like missing the renewal deadline and they won't ever be able to get their domain back. And .edu can only be renewed in the last two weeks before expiration (thankfully now it is possible to pay for three years at once rather than a single one but that's recent).
So, the history of US-centric management of the internet strongly suggest that it's a good idea that countries have and can control their own TLD. Even if a few people feel like their vanity domain name should use what happens to be a ccTLD.