As usual, the difference is energy density between hydrocarbon fuels and Li-ion batteries. Power the drone with gas and it becomes a different story. But then you just re-created the helicopter and all the problems which explain why no one is doing helicopter package deliveries.

I would bet that even the worst Amazon truck gets more pounds of product per Joule expended than the best drone for any reasonably real world distance/load.

The difference is both direct ground contact and fuel capacity.

Even if a drone could carry the energy equivalent of a 20 gallon fuel tank with it, it would waste the majority of that energy both keeping itself and its energy aloft.

Tires and other ground plane vehicles, mitigate the majority of that waste in exchange for increased navigational difficulty (regarding obstacles like buildings and trees but also moving objects like vehicles in its path).

The self-driving robots made some sense but only for very local (couple of block radius) delivery.

And fixed-wing aircraft are substantially more efficient than rotorcraft.

Anything that does not have to be constantly and continuously pumped with more energy in order to not immediately crash is going to be more efficient than the alternative.

A paraglider drone with a tiny parachute would be more efficient than any 3/4/6/8 motor drone copter

Amazon's delivery always felt odd to me because of this exact situation. Long term how sustainable can it be to work on such an extreme scale like that? The margins they must be hiding on via products must be good.

Hovering like a drone has to overcome gravity, which is hard/expensive. A truck only has to overcome rolling friction, which is easy/cheap.

you probably paid at least $5 for that cable, but the cost of materials in the cable was likely less than a dollar

the rest of the money went into the gas tank of the truck

you and everyone else who ordered a cable that day on that route chipped in to fill the truck up

winning response. Thank you for the clarity and simplicity.