> And let's not forget to tax the damage they cause in terms of pollution. Keeping things in the air requires way more energy than moving them over land.
What are you comparing this to? Does this include the energy and pollution needed to move a human, and a vehicle to safely accommodate that human?
> And there are other negative externalities (noise and visual pollution), and also physical danger (these things might crash or collide).
Are these not also the case for human-driven vehicles, which endanger more people (if a motorbike crashes then the rider has low odds), and create noise and visual pollution? I assume the latter means "I don't like how it looks"; if so then does a road look nicer than a drone your eye can't resolve unless you're fairly close to it?