White labelling and counterfeiting are two different things.
White labelling is just rebranding; I go to Home Depot and buy some screws, print out a label that says "jrockway's miracle fasteners", slap it on top of Home Depot's label, and sell them to you, that's white labeling.
Counterfeiting is when you inject seemingly-identical goods into the supply chain. You mix up some soap and blue dye in your bathtub, pour it into some recycled Tide bottles, and ship them off to Amazon's warehouse as "Tide brand laundry detergent". Now you are selling them to customers seeking a genuine product, but they're not getting the real thing.
White-labelling is a perfectly legitimate thing. Counterfeiting is a crime.
To be extra clear, your "I look at things on Amazon before I buy them" technique is exactly the sort of procedure that won't protect you from counterfeiting. The counterfeiters already fooled Amazon. Amazon thinks they're selling you genuine merchandise. But they're not. That's what upsets people.