Convenient, for sure. However, I always have the choice of not giving up my passwords, under (even painful) threat. Also, someone cannot get my passwords if I am dead. Ever. Unfortunately, with biometrics, it is quite easy to force me to put my face/finger/iris in front of the machine and unlock it. Even if I am (freshly) dead. Not that cool, really.
Wow - I guess any apps I build have to satisfy the "If I'm tortured" use case.
You actually really need the three of them. The last one prevents the scenario.