The banks have determined that the cost of preventing fraud is higher than the fraud itself. If you suspect fraud on your account, or if a card is stolen/lost, the fraudulent transaction is quickly reversed and a new card arrives in the mail in 2-3 days.

And it's pretty rare. I've had only once actual instance of electric fraud, and one stolen card in 20 years. That's 20 years of never having to remember or type in a PIN.