There are probably additional correct answers (all depending on the use case/flight plan) but the takeoff/landing profile for a drone vs. an airplane is one answer to your question.
Some people do use airplanes. Bush planes have been used for a long time to deliver things to remote places... ok, well, not oil rigs, but almost anywhere else. Some of them can take off and land in less than 100 feet. Risk of course is that a human is in it. A drone is less liability and less maintenance costs. Planes will still be used for heavier objects and human transport for some time.