I don't think so.

You're describing the total cost and ignoring the larger amount of packages being delivered.

Cost per package drops.

What delivery men need isn't messing around with slow and complicated drone launches. They need the equivalent of a mailbox, i.e. package lockers in front of every apartment building and in front of every house. Then all they have to do is get off the delivery vehicle, retrieve the package, open the locker, insert the package, close the locker and then go back to the vehicle.

At that point you have reached human peak efficiency and then the only thing you can do is build a self driving delivery van with an integrated crane/robot arm to operate the locker.

Self driving is hard. Building a robot arm that inserts packages sideways into a locker doesn't appear as difficult. The post office can dictate the package formats and add visual markers to make it easier for the robot to grab the right side.

Sounds lethal for cyclists and children on toys to pull out a metal rod over sidewalks and what not.

Just put the mailbox so the postman reaches it from the driver seat window.

No SaaS, apps, drones or VC money needed.

I really doubt that cost per package drops more than adding multiple extra drivers.

The truth is that the wave of “imminent drone delivery” mania was always just marketing, and wasn’t going to make sense except in extremely limited scenarios.

Also the drones take up more capacity in the vehicle, as does the charging station, the batteries, the loading mechanisms. And so does the second person. You can carry far less packages now.