以下是Google Bard的解答 There are a few reasons why phones require a backup password or PIN even if you have set up fingerprint unlock. Fingerprints can be spoofed. While it's not easy to do, it is possible to create a fake fingerprint that can be used to unlock a phone. This is why it's important to have a backup password or PIN in place in case someone is able to get ahold of your fingerprint. Fingerprints can change over time. As your fingerprints age, they can become less distinct. This means that your fingerprint may not be able to unlock your phone as accurately as it did when you first set it up. Having a backup password or PIN will ensure that you can still access your phone even if your fingerprints change. Fingerprints can be unavailable. If your fingers are wet, dirty, or injured, you may not be able to use your fingerprint to unlock your phone. Having a backup password or PIN will allow you to access your phone even if your fingerprints are unavailable. On the other hand, there are no security risks associated with only using a password to unlock a phone. If someone were to get ahold of your password, they would only be able to access your phone if they knew the password. This is why it's important to choose a strong password that is difficult to guess. Ultimately, the decision of whether to use only a password or a password and fingerprint unlock is up to you. However, if you want to add an extra layer of security to your phone, I recommend using both a password and fingerprint unlock.