[api]

The worst foot-draggers are major sites like Github and cloud infrastructure. Google only got IPv6 in GKE this year in most regions.

The other big foot-draggers are corporate networks. Even if the ISP supports V6 many corporate networks do not because two generations of IT professionals learned how to do networking entirely through the lens of NAT as a requirement and don't understand how to do things without it. I've seen many IT peoples' brains just melt at the idea of things just having one address. In reality it simplifies things dramatically but sometimes getting people to grasp a simpler solution is actually harder than getting them to grasp a complex one.

I live in the USA and have had IPv6 at home for over a decade (and have used three different ISPs in that time). Many mobile networks are IPv6-first.

[tenebrisalietum]

NAT is a hack and it going away will be good.

That being said, you can do NAT on IPv6 if you really want to, and maybe it will be needed to help soothe those with those emotional attachment to certain numbers. [fc00::192:168:1:0]/120 or [fc00::10:44:0:0]/96, for example.

[api]

Even with NAT IPv6 is better because the NAT can do 1:1 mapping for every IP inside and does not need to remap ports. There is no port exhaustion and P2P always works.

V6 NAT is unnecessary and dumb but it works better than V4 NAT.