NATing IPv4 traffic requires maintaining a 5-tuple of connection state[1], which means the ISP must log these 5-tuples to be able to track citizens individually. Further, if there's another layer of NAT (such as a free WiFi service in an airport or a WiFi router in a citizen's home), cooperation is needed at that NAT layer too.

IPv6 obviates the need to maintain these 5-tuples since it has a larger IP address space. Each citizen can then be assigned an unique IP address which makes it easier to distinguish traffic without the cooperation of each NATing layer.

[1] https://support.huawei.com/enterprise/en/doc/EDOC1100055044/...

Wouldn't people just continue using consumer-grade routers which operate their own nat anyway? Even with ipv6, the traffic generated by all hosts behind a single isp subscription would appear to originate from a single ipv6 host, no?

I highly doubt any consumer grade router is using NAT66. You shouldn't use NAT whatsoever with IPv6 and doing so is just asking for client's network functionality to break.

People who live in developing country like India may use internet connection with CGNAT even for residential connection.

> Each citizen can then be assigned an unique IP address

You don't understand how IPv6 works.

You would want to use NAT with ipv6 if you want to hide somewhat your traffic— say at university as one example.

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No you wouldn't. You would use temporary privacy addresses in your SLAAC prefix (this is the default for a few operating systems)

IPv6 prefix is enough for tracking

IPv6 prefix is assigned on a per router basis, you know, like how IPv4 and NAT already works.

The feedback is fair enough given my phrasing. Of course, IPv6 can't give you a fixed IP address everywhere you go; because that's determined by network topology and IP assignment.

All I'm saying is that there's better segregation of the traffic from each IP resulting in easier analysis without the cooperation of NATing layers.