The other problem is the drones. For this to work you’d be shipping either regular TEU containers or the air freight equivalent (not sure what they’re called but there’s a standard shape I believe), however no drone available today can move either of those. That means new drones, new shipping form factors, or both, and those are both hard problems that you probably don’t want to face when already trying to launch a new freight modality.
You could imagine some sort of futuristic flying Amazon warehouse/drone carrier: It would be pre-stocked at a distribution center, with packets already arranged in a way that they can be picked up by drones individually. Then it floats over a neighborhood while the drones deliver the individual packets to the homes below.