Yeah I can’t get 5 different varieties of a ball bearings in the size I need delivered overnight from Costco. And for the things Costco or your local grocery store is great for, Amazon is often a far worse option. I noticed my wife was buying our toothpaste using a subscribe and save thing, so I compared it to our regular grocery store when I went shopping, and Amazon was like 20% more expensive. Great marketing on Amazon’s part getting people to assume it’s always the lowest price, but it’s often not.
The dumbest assumption I saw Amazon baiting people into was using Chase credit card points for purchases. You'd think spending those specifically on Amazon would be more efficient than just getting cash and buying from Amazon with that cash, right? Turns out it's the other way around, and by a large amount.