Aren't most cellular networks CGNAT? I know my T-Mobile phone is (for IPv4), with native IPv6. I'd like to see more consumer internet be IPv6 first, with a weaker IPv4 to help speed along adoption of v6.
A number of them are. Especially when you get out of first world countries. The problem is that folks who deploy them really hate scaling them up. They believed in IPv6 and the transition isn't going fast enough (sup hosters and cloud providers - stop treating IPv6 as a "customers aren't asking for it" problem and realize this is infrastructure you have to do on their behalf). So now they are stuck paying for v6 CGNAT upgrades or in some cases: running them congested.
Sprin isn't. yet. who knows what's going to happen with the merger. AT&T is though. I'm using OpenMPTCP router to my VPS to both get around CGNAT and aggregate the speed of both connections.
Usually the encumbent/older ISPs still have IPs from the age where they being handed more freely, so they have more than enough to give every customer their own public IP while the challengers have fewer IPs and have to resort to carrier grade NAT. Smartphone plans usually get carrier grade NAT even at the older ISPs.
