This is something I've been thinking about for a while. I agree that allowing delivery drivers/drones into the house is the best solution, and with Amazon I would have no worries about doing this as they would make sure drivers behaved. However for other companies or random delivery companies contracted out... not so sure.
I've been developing an alternative solution. A secure box that you can put outside your home which delivery drivers can request access to. The box's lock is similar to lockitron or bike locks that can be controlled with a phone. This would require the delivery driver to have an app installed to communicate with the box and the owner, which is not always going to be the case. I'm working on allowing the driver to request access by identifying themselves to the owner via voice or video (VOIP/camera) even if they don't have a smartphone/don't have the app.