I suspect this still only works if you can utilize the capacity and have simultaneous deliveries, which would required a cluster of deliveries, thus likely not good for rural areas.
>I suspect this still only works if you can utilize the capacity and have simultaneous deliveries
You can still eliminate inefficient stop-and-go driving for some fraction of stops (ie not U-turns), and (most important) the time-wasting "last 100 feet" walk. Sure it's not as superior in rural areas vs suburban, but with low enough overhead you could still beat a traditional truck.
Naturally if the drone gear cost millions of dollars and took up half the truck, then I'd agree it wouldn't be worth it. In reality I don't think that's the trade.
Who is gonna take the box off the shelf in the truck and attach it to the drone? Boxes are stacked on the truck and move all around, not set neatly spaced on a shelf that doesn't move. You'll need another robot to do that for you.