are they really putting more vehicles on the road though? That is, are they replacing a larger number of people driving themselves to stores with a smaller number of professional delivery vehicles?
Is there something wrong?
If Amazon wanted, they could expand their use of existing infrastructure, namely USPS (which is legally obligated to service homes and businesses) rather than create redundant, poorly maintained secondary infrastructure.
Amazon's FBA program is entirely focused on paying as little as possible to get parcels delivered. There are no living wages, or properly maintained delivery vehicles to be had for the workers that carry Amazon's parcels.
That’s practically the entire story of the consumer economy over the last 50 years.
And more demand is often a bad thing. More demand for meat is straining our natural resources, e.g.