[Detrytus]

The requirement per se is not the biggest problem. Implementation by different banks is. In my country I have several bank accounts.

One bank allows me to install mobile app on up to 5 smartphones, all I need is connect the smartphone to the Internet (e.g. through Wi-Fi).

Another bank allows me to have up to 3 smartphones, but identifies them by phone number, so it forces me to have 3 difrerent SIM cards

Yet another bank will only allow me to have mobile app only on one device. To activate on another device I need to receive SMS code, and if I lose my SIM card I need to show up at a branch in person.

[creer]

Plus the "app" was written by clowns and doesn't really work for any reasonable idea of "work".

[lxgr]

And that's to say nothing about what happens when changing phones...