If people are willing to go to these extents then the biometrics aspect is just a red herring. They kidnap your spouse/child/parent and threaten to murder them

If people are willing to go to these extents then the biometrics aspect is just a red herring. They kidnap your spouse/child/parent and threaten to murder them unless you go through with the transaction. They hold a gun to your head while you transfer the contents of your bitcoin wallet to them. They beat you with a rubber hose until you give them your safe combination.