They instead prefer using a SLD (like .gouv.fr) because they’re complete owner of their ccTLD. ccTLDs are not affiliated in anyway with ICANN. I’m guessing .gov is a special case nowadays, and probably considered like a ccTLD from the ICANN point of view, I’ll have to look into it
Edit: it seems like gov is considered as a Sponsored TLD[1] (sTLD). Not sure what it implies.
ccTLDs delegations are managed by IANA, who are owned by ICANN
While it might be technically possible for ICANN to make certain adjustments to the ccTLD system or the registration requirements, politically its much much harder and gets harder still with time. Imagine the response from most soverign states etc if their own ccTLD was meddled with in a manner they didn't appreciate.
ICANN has slowly tried to move more and more of the ccTLD stuff to international working groups ("Governmental Advisory Committee") to put clean air between the US and ccTLDs, but the link is still there:
https://gac.icann.org/principles-and-guidelines/public/princ...