Half the year I live on an island that is reliant on submarine cables and has historically had weeks and months long outages and with a changing world I suspect that might become reality once again. Locally this wasn't much of an issue, the ccTLD continues to function, most services (but now about 35%) are locally hosted. Then HTTPS comes along. Zero certificates could be (re-)issued during an outage. A locally run CA isn't really an option (standalone simply isn't feasible and getting into root stores takes time and money), so you are left with teaching users to ignore certificate errors a few weeks into an extended outage.

I could see someone like LE working with TLD registrars to enable local issuance (with delegated/sub-CA certificates restricted to the TLD), that could also mitigate problems like today (decentralize issuance) and the registrars are already the primary source of truth for DV validation.