[Cheezmeister]

Fingerprint vs Face shines while (for instance) having a conversation and, because you have manners, want to maintain eye contact while pulling up a photo of that thing you are describing, or to make sure that's just a robocall and not your wife with an emergency.

It also shines first thing in the morning where your hair and eyes are so disheveled that even Siri didn't recognize you. Your thumb is probably still the same shape.

[kstrauser]

> want to maintain eye contact while pulling up a photo of that thing you are describing

Unless your eyes point in markedly different directions, I'm having a hard time imagining how you'd manage that anyway.