Chinese fintech giant Alipay has for some years now had the "Smile to Pay" system: Alipay users can pay for something by just smiling into the camera in an Alipay "Smile to Pay" POS terminal. IIRC KFC was the first place to have it.
I thought you were kidding but who the hell thought this ridiculous concept was a good idea? Putting aside the security implications, did no one see how absurd it is?
What makes you say the phone is useless in folded mode? I had the Fold 3 and 6 and I never really found the front screen to be an issue. If anything, I found it more usable than regular slab phones because of how narrow it is, it makes one handed usage so easy.