I guess you just have more patience with internet search (I find hunting down a specific product on a variety of 3rd party sites far slower and more frustrating than Amazon's search), expensive and slow shipping, and the frustration of oftentimes entering your various details agaaaain into another retailer's online system.

It's odd to argue that, despite all of this relative challenges being pretty objective, you find this approach "as convenient".

(And I never said Amazon is cheaper, although as noted elsewhere, it's often very competitive.)