My current (Bosch) washer does not have WiFi but I can see one use for it: make the machine start the cycle when electricity is cheapest. That usually is somewhere in the middle of the night, at other times in the middle of the day but generally not when I'm there to press some button. Since electricity prices directly correlate with power demand it makes sense to run these appliances when there is a power surplus and not when everyone just comes home and starts turning on their devices.

Of course I would never, ever give devices like this access to the 'net, not even for a few seconds. What 'smart' devices I have around usually run firmware which I installed on them, replacing whatever leaky spyware they came with from the factory. The only exception to this rule is the Fronius inverter which runs its original firmware but just like all other 'smart' things it lives in its own enclave and never got a single bit from or to the 'net. All communications goes through proxies which are under my control, there are no automatic firmware upgrades, no information leaks, no nothing - we live on a farm in the Swedish countryside so there is chance for any 'smart' device to surreptitiously hop onto an open WiFi-network either. Maybe I'll have a look at adding some ESP32-powered wifi functionality to the washer and dishwasher so I can integrate them into the (OpenHAB-powered) control system I use for controlling all things electronic here, something to do for a snowy day?