I kind of regret not buying one of these instead of a Pixel 7 but, unfortunately, I'm pretty tethered to the Android ecosystem at the moment.
But because the banks that require this are cargo culting some nonsense, they require iOS or Google Android but don't really care how old the phone is. Which means you can transfer your cellular plan to the phone you actually want to use and then just keep your existing phone indefinitely to run the bank app over WiFi or tethering.
IDK about your country, but it's also common for banks to require supplying a token from the phone's banking app in order to login via the browser.
Here the majority continue to use SMS based 2FA rather than supporting TOTP or hardware tokens.
Note that TOTP can be handled by any app of the user's choosing, doesn't facilitate attestation or any other user hostile practices, and in practice means that an attack requires physical theft of the device. While the theory might differ, in practice the effective security level is equivalent to other (objectionable) schemes.
The banks are probably using the same standard behind the scenes, but they don't allow alternate TOTP apps. There's no point where they give you a key to set it up in an alternate app.
I suppose part of the point is a lack of trust in users' ability to handle their own security, and the possibility that they may provide such a key to a compromised TOTP app.
> hardware tokens
It'd be excellent if banks moved back to purpose-specific hardware like that. Even better if it were some standard with multiple providers, like FIDO2.
For the user (and in the context of Pinephones), the benefit would lie in getting banks out of their phones. Banks want a device that's not under the control of the user to use as 2FA. A dedicated hardware key would be a compromise for that. They used to give them out, but I pessimistically imagine that today they might prefer to lose a customer.