i think it has to do with them hiring inexperienced delivery drivers who are essentially independent contractors instead of their previous partnership with USPS (which always worked out perfectly for me). i have personally witnessed amazon drivers tossing large, heavy packages up front steps and just letting them crash down with no consideration for what's inside. i wish amazon was as good at treating their employees well as they are at offering affordable prices. maybe then the delivery drivers would care a bit more. ¯\_(ツ)_/¯