Why do Iphone Chargers don't last much time?

I have an Iphone 4s and the chargers i buy don't work after a month or two

My iPod and iPhone accessories work fine years later.

It's likely how well you treat them.

It breaks over time. If you yank it out of your device it can stop working. You have to be gentle don't pull it from the cord. Put your thumb and pointer finger on the end where your device and charger meet and pull don't jiggle EVER