Why hasn’t biometric tech like fingerprints and facial recognition been widely adopted in card payments to reduce fraud and costs?

We will eventually get there. The cost of conversion is enormous. Daniel Lubarov gives great examples as to why it is not being implemented. I want to add further, that the physical card is seeing its duplicate (so to speak) on your mobile phone in the form of a digital wallet. With smartphones now implementing fingerprint scanner, it would be a matter of time before authentication would be done on the phone itself and the token passed for transaction.