A robot dog hiding in bushes for reconnaissance is significantly more energy efficient than letting drones loiter in the air.

Killing people is already a solved problem. Use mortars, call air strikes, send drones, let a heli shoot 30mm rounds, etc.

Why you need a robot dog when some cheap RC car with a $2 camera will do. Anything you can think of that a robot dog can do some cheap bullshit will do better. I am totally not seeing the value of these things.