> dig AAAA github.com > dig AAAA amazon.com

Hm...

It's more likely that the widespread deployment of CGNAT and 464XLAT in mobile networks made the IPv4 scarcity a non-issue. The some CGNAT solutions can multiplex more than 20000 devices onto a single IPv4 address.

I'm a very early adopter of IPv6, and I _still_ have operational issues with it.