So what if instead of being on a hill, we accelerate the drones on launch straight up? Make them bullet-shaped so they don't lose too much momentum. If we lose the requirement of them returning on their own we could also simplify the shell quite a bit. Small wings, guidance electronics and a parachute. Then do curbside collection of the shells once a week.
In summary: Rain the deliveries onto the neighborhood with a railgun.
My packages already show up looking like they were dragged behind the truck. I can't imagine what they'd look like if they got fired out of a rail gun.
In real terms, I'm doubtful that the majority of people's goods would withstand that kind of rapid acceleration. Consumer electronics frequently break from hitting the floor, a rail gun would probably shred them. You could accelerate more slowly, but then you need more runway, and you might end up building a skyscraper anyways to get a delivery radius that's more than half a mile.
In summary: Rain the deliveries onto the neighborhood with a railgun.