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.
We have flying cars, they are called airplanes or more specifically civil utility aircraft. You know, like the Cessna 172.
Flying vehicles aren’t more mainstream because of the cost. A new plane can cost over half a million dollars while a used plane can easily be over a hundred thousand dollars. And that’s just the cost of the plane.
The other reason is because the rules are more strict and are actually enforced. If a pilot flew their plane like the average person drives their car they would be sitting in jail await trail for attempt murder.