[eqvinox]

> IPv6 doesn't make it easy to allocate subnets to every device on a LAN; instead, subnets might be delegated to your local router, and then only individual addresses allocated to each device. If one of those devices then wants to route traffic on behalf of other devices (for example, to a sub-subnet behind a router, where the upstream router doesn't cooperate), it will need to use NAT. For example, this is how Tailscale exit nodes work, even with IPv6.

This is quite wrong, there'd DHCPv6-PD (prefix delegation) specifically designed to do this. Even more interestingly, it has recently been made part of IETF CPE requirements (RFC 9818 update to RFC 7084, July 2025).