Technology

When it's being employed properly, it's absolutely an important tool, but the way they're presented to most users, such as on-device biometric data stores (e.g. Apple's secure enclave, or a TPM verification), aren't the proper implementations. Nor is using biometrics as your primary auth method.

It's supposed to be "something you have and something you know and something you are", not "have or know or are".

NIST standards for biometrics require the biometric data be stored on a secure remote server, and that the scanner device check against that during auth. Putting the biometric data on the device means that you're losing a big part of your non-repudiation.

And it's even worse when you're using a secondary factor (biometric) as your primary or only factor (e.g. a phone unlock), that grants access to your other factors like password store and OTP tokens.

Biometrics are never supposed to be a single-factor auth method when used properly, but that's how most people use them now, and it degrades their security.

If your phone requires a passcode, a TOTP grant, and a biometric scan, by all means, please do employ biometrics, but if it's going to be your only factor, DO NOT.

Or, for simplicity to the average forum reader:

Never use biometrics. It’s just not worth the tradeoffs.