It is probably a matter of what you are comfortable with. I grew up with the "Oh God, I left the Oven on" mentality. As a result I make every effort to shut it down when I leave. Same with the Clothes Dryer. In 60 plus years we have never had any reason to suspect fautly work from either appliance, but I still shut them down.(no we haven’t had the same stove and dryer for 60 years!![:(!])
I will leave the crockpot on overnight or when we go out for an extended time, but I isolate it on a cutting board away from anything flamible…as if that is a real safety measure.
I am sure that there are folks who practice the safety tips that come with the appliances that tell you to set the auto-timer and forget the device and let it manage itself, but thats not ME!
One thing that COULD affect my thinking on this, most of my range and dryers have been gas-powered…They work very well but Open flames make me nervous. We now have an electric dryer, but the stove and hot water heater (and furnace) are all L P Gas. And that can be a concern at times.[:(]