In Europe ground fault interruption is mandatory, as well as breakers that trip at a relatively low current at a fast speed. All of the wires are also at least double insulated with heat resistant plastic. The appliance is more likely to get replaced due to old age rather than the wire wearing through. And even if it does, the ground fault interruptor kicks in right away and prevents anything bad from happening. The owner investigates, buys a new cord for a few euro and easily replaces it.