On my cables the material starts to crumble and crack. Something about that particular type of rubber. But maybe it depends on the market or where it is manufactured. I seem to remember some lasting longer than others, I think it didin't happen on the 2014 model, but did on my original 2011 charger and on the replacement I had to buy (within the first year). But the 2016 usb-c cable doesn't really have this issue I think. Maybe it's the climate, warmer summers?
I found that this happened if you are around cigarettes. Once I moved away from that family member, I’ve not had another one die in that fashion since.
