With respect to (1), why would delivery drones fly at high altitudes? I suspect that the only overlap in the flight envelopes of delivery drones and of manned f

With respect to (1), why would delivery drones fly at high altitudes? I suspect that the only overlap in the flight envelopes of delivery drones and of manned fixed-wing aircraft will be riiiight around the airport, and during horrible plane crashes. (Manned helicopters are another matter, but how many of those are there really? Even in the big cities.)