You did in fact say "drones". It was the very first few words of your post - "If you use drones/"
What I said was "drones/robots/self-driving cars or some combination" - clearly indicating any and all. Not "drones" per se.
But even military drones can't cope with all (or even most) weather.
Today's tech is not the end game by any means. So using today's capabilities to make claims about tomorrow's likely circumstance needs to extend the progress curve before it can be taken seriously. IOW, the fact that a military drone can't cope with some weather at this time is in no way an indication that the same type of drone won't be able to in the near future (and the progress being made in LDNLS systems is a very strong indication they probably will.) Same for everything else. What it boils down to: Yes, today there still are lots of delivery jobs. But in a not-too-distant tomorrow, there won't be. Same for many other sectors.
Prepare or be blindsided. It's just that simple.