Smartmeters don't currently do anything that couldn't be done previously by sending a small boy into the cupboard under the stairs with his father's watch, a torch or candle, and the instruction "see how long it takes for the wheel on the meter to go round" any advantage is in computer software which makes the task of analysing consumption easier.
My worry is the remote disconnect facility - https://forums.moneysavingexpert.com/showthread.php?t=5607490
The energy companies may say they would never use this; but what about in ten years time, when it's all watched by the same computers that automatically decide now that you haven't paid your bill (don't you ever get those erroneous letters?); and in the future may turn your supply off without any human intervention? Have you ever tried to argue with a computer?
Of course catters may be able to help each other with instructions on how to hack into the utilties computers!