That truck carries 500 packages. That drone one or two at best so to replace one truck you're looking at 100's of flights + return flights. And I'm not convinced the risks are lower.
Heh, you've not heard my neighbors riced out car then.
But the biggest harm is people getting hit by vehicles. Delivery drones are much smaller and don't spend nearly as much time near people. Since drones can deliver stuff more quickly than large vans, they also substitute for individuals driving to a store to pick something up. So the total risk to pedestrians is even less than you might expect from eliminating many van deliveries.