On a large commercial network, there's a distinct 'backbone' and self-controlled 'iot' and 'end users', and of the 3 only end users need v4. Compare that to a h

On a large commercial network, there's a distinct 'backbone' and self-controlled 'iot' and 'end users', and of the 3 only end users need v4. Compare that to a home environment where there's pretty much all devices need v4, and there aren't too complicated firewall rules going on, it makes less sense to split into a backbone and v6 only devices. Still, you could do it using something like DNS64 if you really wanted to.