The biggest issues with delivery robots are exactly what you'd think

Engadget 

Despite their problems, robot delivery likely isn't going to go away any time soon; on the contrary, it's predicted to vastly expand. A recent study by Transforma Insights suggests that the world will have 559,000 automated urban delivery vehicles by 2035, compared to 28,000 in 2025. Considering this prediction, this robot revolution could have a big impact on gig workers. For companies like Uber Eats and DoorDash, both of which have faced scrutiny when it comes to paying their drivers ethically, robots are an easy way to increase overall company profits. However, the distance limitations of current robot models -- about two miles -- tend to limit their usage to more urban areas, meaning that, at least for the time being, humans cannot be completely taken out of the equation.