I've never had an issue with Amazon delivery until they used their own drivers. I now frequently have my packages never arrive (I have cameras on my porch. Not being stolen) and four times in the last six months have received a delivery for someone else. It isn't like a package for my next door neighbor, either. They're packages to addresses up to three miles away.
If Amazon wants to reduce missing packages, they need to hire drivers who actually give a shit or go back to using USPS/FedEx/UPS.