«A more proportional system is more voter sensitive and more voter reactive system than we have at present.» (theguardian.com)
Bentley's adaptive and reactive system provides variable torsional resistance, allowing the Bentayga to be both dynamically capable and comfortable for all occupants at all times. (cheersandgears.com)
The other answers touch on why having two - factor auth or some other additional system is not worth it compared to simple reactive systems (cancelling lost cards, reversing fraudulent charges etc), but it should also be noted that this goal can be achieved with a method similar to what you describe. (money.stackexchange.com)