I refuse to own an oven that is internet connected. If my oven has enough of a computer to have a firmware that can be updated remotely, it is too dangerous to own.
Imagine an attack on the electric grid that works by startíng a large number of high-power appliances (ovens, EVs, ACs/heat pumps, etc) at max power at the exact same time.
If the grid is very slightly over 50hz it means demand exceeds supply and vice versa.
By automatically switching off the pump on thousands of fridges for a few seconds, networks would require less generation capacity on standby - saving $$$ and CO2.
Of course, like you say, this would leave potential for this to be used in reverse to destabilise an entire grid.