Biometrics is biometrics. I like to think of it sitting between a continuum between "username" and "password".
I might like a setting to require both a Touch ID (or Face ID) and a passphrase to unlock my iPhone. However, Touch ID has flaked out enough times for me (not accepting my fingerprints) that I probably wouldn't like to risk it in practice.
Passwords can be changed and are secrets. They're authenticators.
The difference between them is exactly the difference between identifiers and authenticators. Misunderstanding this difference causes tons of issues, in a wide variety of situations. The most notable one recently is probably Social Security Numbers being used as both, which leads to identity theft.
This will probably matter less once our future devices can interact with our sci-fi personal nanites, or rfid implants in the meantime.