A huge swathe of smart devices literally just need some way to turn them on or off without needing to be right next to them. A kettle, for example, that could be activated a minute or two after my alarm goes off so it finishes boiling as I step into the kitchen would be quite nice (though not terribly necessary). Equally, an oven or air fryer that could be turned on remotely to pre-heat might be nice.

But honestly, I don't have a single smart appliance in my kitchen, and I can't say I'm the poorer for it.