If I were a breaking bad meth dealer and had all my buyers as contacts on that phone and all my incriminating chats, I wouldn't use biometrics to unlock it. But I'm not a meth dealer (and I'm not just saying that because that's what a meth dealer would say).
There is a spectrum of convenience vs. security. It depends on where you sit. I'm okay with the fingerprint, wouldn't go for the face.
Doesn't Android have the panic/cop switch where you force password over biometrics unlocking? It's not a 100% failsafe but it is a start.
(and I'm not just saying that because that's what a meth dealer would say)
Hmm sound like something a meth dealer would say
And yeah android does have a lockdown button, if you press and hold the power button, its in the options.
Alternatively you can quickly spam the wrong finger over the sensor a few times until it requires the pass code, which will work for iOS too.
Edit: after a quick test the "wrong finger" method has a a fatal flaw. After using the wrong finger a few times, the pass code UI appears. If you back out of it you can still use finger unlock. You have to get to the code UI and back out 2-3 times before it says too many failed attempts and forces you to use the pin.
It may vary between models. Mine if you spam the wrong finger it just counts down 30 seconds before you can try again. But restarting does force a pass entry before fingerprint will work again. I guess the caveat is you have to be able to hold down the power and then select a restart.
I don't want to test this right now, but some of my previous devices would just reboot after keeping the power button pressed for approx. 10-30 sec, overruling the need to use the on-screen shutdown menu - probably to be able to escape a frozen/broken system without waiting for the unremovable battery to run out. That could very well still be the case for some current devices out there.