>The consumption of products via delivery has become too high for anyone to keep up.
Our little rural post office is broken. Rural Carriers are having to return to the office multiple times for Amazon packages as they can't get them all in their vehicles. This adds miles to the route, for which they're not adequately paid.
Amazon is the problem.
>why hasn't the Post Office procured appropriately larger vehicles, in the face of paid demand?
Rural carriers furnish their own vehicles and get paid an "Estimated Mileage Allowance". The larger the vehicle, the more it costs the carrier to run so they run the most economical vehicle possible. They pay for fuel, maintenance, tires, insurance, towing etc and the PO gives them a fixed stipend. Duplicate trips back to the office eat into the EMA and have caused many carriers to just give up and quit.
Long hours, low pay, dedicated vehicle (that gets trashed on dirt roads), it's not worth it anymore.