A thief flags you down, grabs your phone and makes you unlock it using your thumb.
A cop opens the cop car door, grabs your hand and unlocks your phone, or even easier, face unlock.
Granted, guns and torture are rather effective as well, but is anyone entirely against fingerprint unlocking?
if biometrics is the only thing you have you might aswell not have a password at all but if you use it with a 2fa pin it is good for example for your phone yiu can have a long backup passphrase and if you dont want to type that in you can use biometrics to unlock the pin screeb and still need to type in a pin so its the best of both worlds