[cancerhacker]

Here's a thought: vehicles that are already scheduled (uber or robot-taxies) are already scheduled from point A to point B. Drone scheduling could piggyback on this such that as large vehicle passes restaurant R at A', a drone from R lands and disgorges your sandwich into a locker mounted on a landing pad on top of the taxi. (hand waves - that's just a mechanical problem, can't be worse than what a fast food place is doing.) As the ground vehicle approaches B, a new drone (or the same drone, if it was just hitching) could finish the delivery to your home H at B'.

Obviously it would take a lot longer than a direct flight, but the energy consumed would be far less.

Or, people should just make a sandwich.

[Hextinium]

A network of "wardriving" drones that use semi-trucks and box trucks as charging hubs while in transit is the next innovation of short distance delivery.