They don't have giant DARPA allocated IP4 blocks handed out for free to companies and universities in the early days of the internet either.

Exactly. And as a developing country, they (hard guess) do not have the widespread pre-existing infrastructure like developed countries; and therefore can easier to adopt to it.

Another factor - mobile has a way greater market share in India, than mobile has in Europe. It’s easier to enforce IPv6 as a mobile carrier

(https://gs.statcounter.com/platform-market-share/desktop-mob...)

How does China manage?