Of course there is. Assembling a drone with a leash upgrade produces a drone that can transport cows, horses, sheeps, and pigs. Like this:
Or... like this:
Besides, drones are entities. They move in straight lines; they don't get stuck in the fence and can actually enter a house through a door. They move pretty fast — about 6 blocks a second (robots are at least 2 times slower). Drone's movement is asynchronous, so the machine can execute some other code in the middle of the flight. Drones can fly above the block height limit. The screenshot above was made while enjoying the flight at a height of 260 blocks, for example. Oh, they can fly below the bedrock, too.
Also, drones look cool.
Jobs at which drones clearly outperform robots include player transportation (thanks to the leash upgrade) and item transportation (due to their mobility). And, if used with robots, drones can be useful for crop farming, autocrafting, and construction, for example.
