a) that's not the case in many places, as demonstrated by what happened in Afghanistan, where control over the ccTLD now lies with a group of religious extremists
b) you have no guarantee that the happy state of affairs with your ccTLD will continue. Governments change, and so do politics.
Corporations don't exist in a vacuum, they're subject to the laws of the jurisdictions they're incorporated in. Corporations aren't permanent and unchanging, they can pivot in unexpected ways or enact arbitrary decisions that may affect you.
Most people just get to pretend gTLDs are safe from politics because most gTLDs are ultimately under US jurisidiction and even outside the US we often treat that as the default. The mistake of the people using dot-af domains was to treat af as if this is also true for them - which even prior to the US retreat wasn't a safe bet.
What's also missing from the discourse around `queer.af` is that they were merely one domain of many affected because the Taliban withdrew from Gandi (among others?), not just the people running that Mastodon instance. It's just the most obvious example because of the nature of social media.
Until it doesn't. Corruption and coups are a thing.
I know DNS has a terrible centralized design, but what is the alternative?