If we could push an AI controller to the point of having the intelligence of a cat or a dog, we would be able to make transportation equipment that would blow the wheels of of anything else we currently know. Having equipment carts that walk with you, baby carriers that do the same, and have zero issues with stairs, doors, ... (and yes, the military applications I'm sure are wonderful too). The dream would be that you'd have a mobile robot that can deliver packages. Packages the size of refrigerators and that could deliver them in your kitchen, walking in through your door, walking up the stairs/taking the elevator if necessary, ring your doorbell, ... Not to mention the industrial applications. Such robots would enable reconfigurable factories : the robots doing the work simply walk over to their new positions.
Even that would just be the beginning.
Then suppose we get there, can we go further ? Flying animals have extreme advantages over our airplanes. What if you could design a 4 seater airplane with legs and wings like a duck ? A large airplane that could reliably land and take off on a runway shorter than the length of the plane in strong crosswinds. And yet have that plane capable of maintaining flight for hours, far exceeding the endurance and efficiency of helicopters.
What I'm saying is. A lot of limitations of our current state of the art vehicles are effectively a control problem. Building a legged robot is not a problem at all, yet it would have massive advantages. Building a winged robot is harder, but certainly within the realm of possibility. Yet we don't have them. Why not ? We can't control robots like that (see youtube).
Let's fix that.