In Germany we have a trial run of food delivery. A drone will bring a package with up to 4.5 kg to a "remote" village, then some students on e-bikes will bring it to the houses. Why they are using drones instead of one lorry a day is unknown.

I've seen videos of a firm doing interesting stuff with bigger "mothership" drones that hover much higher and then lower a much smaller drone like thing on a cable to place the parcel on the ground. They can hit pretty precise targets and can maneuver around more obstacles than bigger drones can.

All that needs to happen is for the tech to advance to the point where it's cheaper to do x% of their deliveries via automated drones than it would cost to have delivery drivers do it and they'll start doing it. Saving millions(billions?) by say halving the number of human operated delivery trucks will make it a no brainer for them.

In all of the above, where either the landlord or the recipient specifies (and when it's decided by the landlord, the buyer gets precise location info to pass to Amazon when buying stuff, which would include instructions for how to retrieve it after delivery)

In all cases the property owner would be responsible for ensuring there's a suitable landing location. Preferably combined with lockboxes which drones can directly deposit packages to.

I agree with the others that aerial drones is usually not the most efficient. But in some cases the destination is complicated to reach by foot and then they're useful. Otherwise land based drones could easily be used (imagine a Segway style delivery bot!)