I have been an Amazon Prime Member for two years now. I placed 5 orders last month, 3 were late, one was lost and, only one made it on time.
Also if you pay attention, the Prime shipping rates are added into the price of what you order. If you check the other vendors and you will see lower prices for your item, but when you add their shipping it comes about the same as the Prime member offered price.
Amazon is not "giving" you anything for your membership fee. Seems Amazon has run its coarse as a quality company.
Product or Service Mentioned: Amazon Membership.