Only one item can be delivered at a time. It can’t weigh more than 5 pounds. It can’t be too big. It can’t be something breakable, since the drone drops it from 12 feet. The drones can’t fly when it is too hot or too windy or too rainy.
You need to be home to put out the landing target and to make sure that a porch pirate doesn’t make off with your item or that it doesn’t roll into the street (which happened once to Lord and Silverman). But your car can’t be in the driveway. Letting the drone land in the backyard would avoid some of these problems, but not if there are trees.
Amazon has also warned customers that drone delivery is unavailable during periods of high demand for drone delivery.
… and they can get robbed or kicked, their sensors sprayed shut… and repair costs a fortune. I don’t think delivery without a human makes much sense, maybe except for a drone that delivers to the Australian outback or a small island at the German coast.
They want desperately to cut delivery cost by taking out the human they have to pay for it to do the work. To do so they spent billions they could have used to pay these people a decent wage and hire more of them. It is dumb.
Solution: every 17th drone is a decoy carrying a paint bomb to mark anyone who robs it or were just standing around not trying to defend it or defending it effectively enough. Then the Amazon corporate police can swoop in and deal with anyone with paint on them.
There are ways to prevent that, like alarms, notifying the police. These robots will absolutely have ways to be tracked at all times, cameras and all. You could also only use them for low value packages, so the effort is less worth it.