Re: What was that quote allegedly from Cardinal Richelieu again?
Why would this have to be per-household rather than per-substation if that is its main purpose?
I suspect at least partly because of this 'leccy car fad they're expecting people to provide their own multi-kWh storage that they can raid because they've sold off public infrastructure and haven't planned for the future. The problem with that is every charge/discharge cycle is one more step toward the grave for the most expensive part in your unicornmobile, which is a good thing for the manufacturer and The Economy™ but bloody awful for the poor sods who have to pay for it and accept the feature disparity between grandiose milk floats and proper internal combustion.
I do hope everyone caught the "mandatory smart¹ elctrojalopy charge point in every new build" proposal. When you gather all the evidence together it becomes obvious.
¹ Monitors and reports energy used to charge, storage capacity and so on. They then know where all the big capacitors are. I give it five minutes until they start collecting geodata, timing and usage stats for road pricing through the same pipe.