The plastic adds enough rigidity overall to help resist bending. The combination of the metal inside and the overall thickness of the added plastic is pretty good. It won’t resist a Hulk smash or a tank rolling over it. But it should, hopefully, resist routine bending forces during packaging and shipping. Goof around with it the next time you receive one, and you’ll see what I mean.
but a simple plastic bag would be enough for that?
The plastic adds enough rigidity overall to help resist bending. The combination of the metal inside and the overall thickness of the added plastic is pretty good. It won’t resist a Hulk smash or a tank rolling over it. But it should, hopefully, resist routine bending forces during packaging and shipping. Goof around with it the next time you receive one, and you’ll see what I mean.