How do you get around the battery life and range restrictions? Take the
Mavic Pro 2 for example, per DJI the battery will last for 31 minutes at a consistent 15 mph, for some reason I can't find range, but I am finding 8,000 m / 5 miles (feel free to correct me if I am wrong on that). At it's max flight speed of around 40 mph your battery is not going to last as long as that 31 minutes.
So, let's say you fly at 15 mph for 31 minutes (even though, there is no chance you are getting a full 31 minutes in anything other than perfect conditions, something that is pretty much not going to happen in the real world). 15 mph for 31 minutes, lets round it up to 8 miles covered. But, the range tops out at 5 miles, again, from my understanding in ideal conditions.
5 miles max distance at 15mph is 20 minutes, leaves you only 11 minutes to make the return journey, you'll be out looking for your drone at about 2.25 miles from the take off point after it crashes since the battery ran out. To make it to the delivery point and back before the battery runs out, you are looking at a distance of only 3.75 miles. Works for the range, but 3.75 miles, I don't see how that works for deliveries, most people would sooner get in their car and drive that 3.75 miles to pick something up.
This all ignoring the fact that if you are carrying something on the bottom, in real world conditions, that battery life and range are both going to decrease.
The only way I see it working is if you have a network of drone operators, so pilot 1 flies 3 miles and drops the package off with pilot 2 who flies a further 3 miles and so on. If this is all explained somewhere, let me know where, I would be interested to see it. As is though, I cannot see how it works both reliably and in a way that makes any sense.