An interesting theory, we certainly do have reasonably robust consumer laws.

I just happen to have a typical box that drives ship in. It is 8x6x4 inches, where all the space not taken up by the 3.5 inch drive is taken up by dense good quality foam. I have no idea how that compares to shipping boxes elsewhere.

If you order from Amazon you can of course end up with one of these robust boxes further packaged in an Amazon box with extra padding. Typically from dedicated computer retailers they just post the box the drive comes from the manufacturer in.