In a perfect world, where IoT stands for Intranet of Things, IoT companies do actual engineering, and turning products into services is illegal?
In that world, the use case isn't cooking food from across town. It's cooking food from another room.
I'm sitting in my home office right now. I'm working (well, on a HN break :)). My wife is playing with our child. I'm thirsty and I want a cup of tea now. My choices are either to distract myself for a couple minutes, which is annoying if the thirst hits in when I'm "in the zone". Or I could ask my wife, but she has better things to do and I don't like interrupting people unless it's necessary. In this perfect world I described at the beginning, I could just press a button on my keyboard to start the kettle, and would get a pop-up notification once the water is ready. I'd just get up and get my tea without losing focus, and without distracting anyone else.
Similar reasoning for other appliances.
Unfortunately, the way IoT is developing, I don't expect that future any time soon, because some of the features are in opposition to the business model under which IoT companies operate. A better bet for me would be to get an EE degree and mod the appliances myself (I'm not doing it now, because I'm afraid of letting my contraptions control anything that's connected to mains, or could otherwise start a fire).
EDIT:
Another way of putting the value proposition of IoT in a sane world: rich people hire assistants to handle trivial and distracting errands. IoT is supposed to be an equivalent of that, but available to everyone.