Why is the PIN so important? It only protects a very narrow scenario: your card has been physically stolen, you haven't noticed yet, and the thieves try to use

Why is the PIN so important? It only protects a very narrow scenario: your card has been physically stolen, you haven't noticed yet, and the thieves try to use it at a physical location which verifies the chip (some places still let you swipe...). The chip itself protects against cloning and if you've notified the issuer that the card is lost/stolen they'll cancel the card number so it will become worthless.