Maybe I'm out of the loop but what is everyone doing with banking apps on their phones that's so essential. I see this argument all the time but it's baffling to me.
MFA largely, some banks also provide wallets for contactless payments.
I refuse to have my browser fingerprinted as a "trusted device" because part my bank is just bad at it.
Paying for things? Transferring money? What else do you do with a bank account?
For quite many banks a mobile phone is now the only 2FA they support.