Unfortunately VCs were much less interested in funding R&D of rolling autonomous robots in the past few years, so they aren't going to happen all of a sudden when the world actually needs them.
I do agree though that they make a lot more sense than drones, for several reasons: (a) power consumption / mileage per charge (b) carrying capacity (c) safety in populated areas (d) privacy when flying by buildings (e) lack of suitable landing areas in urban centers (f) noise in residential areas.
Source: I am the co-founder of one and aware of internals of several others
Safety I wonder. If they are only carrying 5lb packages having them fall from the sky sound bad but the frequency of rolling robots causing car accidents or running over people or getting smashed by locals might make it more safe.
Car accidents typically involve a car running into a robot, which might obliterate the robot but would seldom cause injuries to the driver. Delivery robots would almost exclusively operate on sidewalks of 25 mph, maybe 35mph roads. Running into someone is also unlikely to cause serious injury if the robot is kept to a reasonable size and weight limit. Obstacle avoidance and bump sensors are trivial to implement. Drones, on the other hand, can take out eyes and cause severe injury if they impact someone in the face with spinning blades, and crash avoidance mid-air involves an advanced control loop as opposed to just cutting power to motors.
Well, I agree. The idea of a UAV with a 2m wingspan landing somewhere near my house to deliver a 5kg package sounds like it could cause a lot of injuries. The delivery vehicle has to be much larger than the package and it has to land near a spot that is accessible to humans so they can pick the package up. As soon as you have flying drones they will have to get near other humans. Ground robots have a huge advantage in that they are less dangerous to humans. Do you really think something that is designed to constantly cooperate with humans is going to fare worse than something that will be near one for a minute? It's very likely that the UAV companies don't test their landing programs sufficiently.
I do agree though that they make a lot more sense than drones, for several reasons: (a) power consumption / mileage per charge (b) carrying capacity (c) safety in populated areas (d) privacy when flying by buildings (e) lack of suitable landing areas in urban centers (f) noise in residential areas.
Source: I am the co-founder of one and aware of internals of several others