I think machines can help people do some things to a certain extent, but after all, machines are just some settings of programs, and they can't think completely through the brain like people.
Let's take a simple example. When we receive express delivery, sometimes the goods inside are damaged or lost. At this time, we need the presence of the courier to communicate and negotiate. However, if we are a drone at this time, it is difficult to get more effective communication results in the face of such sudden random events.
In this case, people must be involved. What could have been solved at one time has turned into two handovers, and the cost will definitely go up when compared, so I think it would be better to rely on human delivery for express delivery. After all, the machine can't be so humanized.
like myself, sometimes if people are not filling in the receiving location, they will temporarily change a place and ask the courier to help deliver it. I think it is still difficult to achieve such a request by drones.