Cooking when/where energy is scarce. Very useful to save on fuel while camping, for example. Also, I suppose, next time the electric grid is down and you want to cook on battery.
Another benefit is that it reduces the heat transferred to the living environment during cooking. Might be useful in a small living space like an RV or tiny house.
A lot of people out in the country don't actually have a gas line to their house, and cook using bottled gas. I lived in a situation like that at one point - the cost of the gas saved by the device wasn't really important to me, but it was the burden of making a half day trip to the city to replace the bottle that pushed me to conserve gas.