Your iPhone doesn't even really store your biometric information, it stores mathematical models that can be used to check whether the fingerprint (Touch ID) or face (Face ID) matches the person who enrolled on the device (you).

And that mathematical information is only stored in the Secure Enclave, which means even if the entire Operating System (iOS) is hacked, the attacker still would not have access to your biometric information.

You should read this page. It goes into great detail about how much security there is around Touch ID and Face ID: https://support.apple.com/guide/security/face-id-and-touch-i...