This doesn't seem like it will work outside of their video with the perfectly well maintained sidewalk.
1. How many packages is it carrying? What stops someone from taking other packages?
2. You have to come outside to get your package from the robot? How long will it wait? I want my packages dropped off at the front door.
3. It won't roll up to your door? I don't want to go to the sidewalk for a package.
4. How does it identify you?
5. How does it deal with unpaved areas, rough terrain around a house?
If it can do this job at a significantly reduced cost for even 10% of Amazon's customers, that could be 10s or 100s of millions of dollars saved annually. It probably scales better in certain environments too.
1. Who knows, security seems very solvable, and some security is better than none (our current reality). Package volume could be scalable.
2. Not everybody cares about this; a good portion of the market would prefer this to a package left on the doorstep.
3. Same as (2) above; for me, this would be an extra 8 feet or so of walking, but everybody's situation will be different.
4. Same as (1) above.
5. Likely wouldn't serve these customers, who are probably a minority of customers anyway