Before iPhones had biometric authentication, a PIN was the only means to unlock the cryptographic key that protects your data on the phone. It still is; you can

Before iPhones had biometric authentication, a PIN was the only means to unlock the cryptographic key that protects your data on the phone. It still is; you can bypass Face ID and Touch ID at any time by entering your PIN. So it's not like this is a new thing. It's the same concept, but applied to a PC as well.