It is worse than that. They implement 'carrier grade NAT' on top of double NAT. Maybe mobile devices don't need incoming connectivity but doing a hack on a hac

It is worse than that. They implement 'carrier grade NAT' on top of double NAT. Maybe mobile devices don't need incoming connectivity but doing a hack on a hack to save IPv4 addresses is a reflection on the genuine expertise at some of the national carriers. When I was younger, telecom providers had all the professional expert engineering talent. (I'm on superloop down under here, they actually have engineers and seem to have deployed a, what seems to be to me, a faultless IPV6 setup. The only issues I have found have been with toy things like pihole not behaving properly. Once I went to the Technitium thing my ipv6 experience over the last few years has been faultless.