Most mobile phones are v6 only and then go through increasingly unreliable CGNAT setups for v4

So they are not IPv6 only if I understand well. Why a CGNAT would be unreliable?

Yet another over-subscribed device to rewrite packets between you and your destination. Spontaneous connection failures due to port exhaustion or overly aggressive connection timers/recycling. Lack of public to private connectability due to absence of port mapping, or any way to influence the configuration of your carrier’s device.

Unfortunately, AT&T doesn't give my phone a v6 address.

> How many humans browse internet with IPv6 only devices?

If you browse the net on your phone, it's likely you already do or sit behind some kludged up NAT situation which - among other things - severly curtails your freedom to interact with other devices on the internet.

And things aren't going to improve in that regard given the shortage of V4 addies.

True, but it's not IPv6 only devices.

You might have missed the "or" word in my sentence.

some humans do.

https://news.ycombinator.com/item?id=31715661

Interesting, so one stubborn guy in USA who decided to sell broken internet access to its customers. I'm sure they are happy, if this story is true.