Re: So who decides what is necessary?
Rephrase in case you're a pure IT chap:
Smart Meters are an IoT device allowing remote control at power/current-delivery levels of every individual/separate circuit attached to it, from a remote location.
The traders were crowing 10yrs ago that their screens let them casually control not just by area, but way past the substation level they used to pine for, but effortlessly down to postcode level. "You just click down!" For non-UK people, bear in mind that UK postcodes are per-street or part thereof for "long" ones (eg over 200 houses). And you could keep clicking...
Head Trader on one desk when the software was first installed, first day early morning , exclaiming, kept clicking down and "switched off" his own fridge. An hour's drive away. "AWESOME!!" Had to re-buy a week's worth of food. "Worth it! That's awesome!"
That was 10yrs ago.
Smart Meters are the first mass IoT rollout.