Drone delivery is never going to work. The vehicles have to be lightly-built, which makes them vulnerable to attack; and they are carrying valuable payloads, which makes them attractive targets. There are people out there who don't like the noise, people who want the cargo for themselves and people who just want to spoil things for other people. It's a hostile environment, full of projectiles, RF jamming devices and nets.
If (or more probably when) a drone delivery fails, you are out of pocket to the tune of a new drone; and even if you can make the drones cheaply enough to regard as disposable, you have to pay to replace the cargo
Contrast this with a more traditional method of delivery, such as a human being on a bicycle; you only have to pay them when the item is successfully delivered, and (depending how you worded the contract of employment) you might even be able to recover the cost of the goods from them if the package goes astray. Which is less likely in the first place, because people are generally better defended, especially in more substantial vehicles than bicycles.
If somebody is wanting drones filling the skies, you can be sure it's not really for delivering parcels.