Since I wrote the original post I learned that the phone payment systems can be tied to a credit card. So the consumer may not have liability if the phone gets hacked. Of course nothing is free. The credit card companies pay for their losses through fraud via higher fees.
Convenience beats security, until you have a lot to lose. The Amazon account for nderground uses two factor authentication. It’s not as convenient as just using an email address and password. But it greatly increases security for a critical account. Two factor authentication is also used for one of my bank accounts and for my stock market account.