I mean i guess yeah, same way a schoolbus is just a light armoured personel carrier.

Flight is way faster than following traffic.

Dynamic targeting is necessary cause a lot of people don't have mailboxes that take packages and skipping those saves you having to develop some kind of tactile device to even use mailboxes in the first place(that would be even more difficult and scary for you, imagine if they could open doors😱).

UAVs were first developed for military use, you can draw paralels to that market from any drone, that doesn't suddenly make it scary.

There's way cheaper and more efficient ways to makes combat UAVs than first developing a whole civil version and then suddenly adopting it for other purposes. That's unnecessarily complicated.