What exactly is easy about flying drones? Hovering in place? Flying in a straight line for a mile? How about autonomously navigating air traffic? Navigating 3d

What exactly is easy about flying drones? Hovering in place? Flying in a straight line for a mile? How about autonomously navigating air traffic? Navigating 3d space, full of unexpected obstacles? We don't even have sensory devices that would enable true autonomous drone flight of any complexity beyond trivial.