Could be how your bending them. I hate earbud jacks that dont curve. They always bend and im out of hearing in one ear. Its wire tear from overtime use. The more the wires bend the more likely it is to break. Dont crease them if you fold them. Thats bound to break it. And this could happen during outdoor use. If its in your pocket when you run, it tugs and pulls. It even bends them.

Regardless, earbuds are bound to break through wire tear. Earppds have won the market but damn. They expensive to replace if you lose em often.