Why aren't we using drone blimp/hybird airship for delivery? Currently, the heaviest weight a commercial drone (the type that delivers Amazon package, not the type that delivers tons of stuff) can lift is 4.5kg with a 30-45 minute battery life. A drone blimp/hybird airship might be bigger and slower, but it would take less energy--the lift is generated by the balloon or some lifting surface instead of the propellers. Since the Boeing 747 win against the Concorde because it can carry more people with a cheaper price despite much slower than Concorde, why aren't we using a drone blimp/hybird airship to deliver Amazon packages instead?
There are many reasons why that will probably not happen.
Number 1: As of right now drones/blimps are very big for 1 package. It is much more efficient to use a car that can take in hundreds of packages.
Number 2: There are may types of drones/blimps that can be flammable exposed to certain chemicals. Also...where is the drone gong to fly? In airspace where planes are? Where is it gong to land? What about apartment buildings?
Thats why this is not plausible. Maybe one day it will.