My solution to this problem (and yes I've noticed the same) is to generally pay the price to change to one-day shipping which never (so far at least) goes USPS.

My solution to this problem (and yes I've noticed the same) is to generally pay the price to change to one-day shipping which never (so far at least) goes USPS. Of course we are in one of the areas with Prime Now service, and I am willing to consider that this may be to make me think "Do I pay a driver a $5 tip if the item(s) are available or pay $5/item for one day delivery".