Nothing, in my opinion, but I do have a sort of funny story about IoT thermostats.

My SO's dad is a gadgets guy, and he travels constantly for work. He is also incredibly vigilant about bills. They're the kind of family that can't touch the thermostat until a certain time of year, weighs insurance costs into every decision they make, etc.

Anyways, when he was traveling—even in cold months—he would see the thermostat going up on his phone and panic, turning it down. His kids, who were freezing in the house, would turn it up again because winter, and several hours later the cycle would repeat. They were basically locked in a constant battle to warm their house against their miserly dad and the cloud.