my thought is that biometrics is an additional layer of security and not just a different layer of security
I have to agree with this at the moment they are not an alternative. Perhaps creating a devise that was brought to our attention in this thread Smart guns where this link might be a solution to increasing the reliability of FP reader. Perhaps in time both technologies will be integrated and you will have a system where your fingerprint will be linked to your hand readings as well as your account adding 2 layers with one devise.

Kindred69