Every banking phone app I've used auto-logouts after being idle or unused for a bit, and my primary bank's app requires 2fa using an app that exists on the same device -- a second factor that secures nothing. They probably are not explicitly considering the phone more secure than a computer, but rather a good 80% of this is security theater or a checkbox on some baseline security checklist that was implemented without really understanding what the implications, for usability and security, were going to be.
> 2fa using an app that exists on the same device -- a second factor that secures nothing
2FA on the same device secures against your login credentials becoming known to another party, e.g. by fishing, password reuse, database leaks, etc., which are real threats. It is not meant to protect against someone being in possession or full control of your unlocked device, which is of course also a real threat, though possibly less common.
> 2fa using an app that exists on the same device -- a second factor that secures nothing
If I steal your device, and you didn’t have faceid, I have both factors. But if I steal your password, or find it in a leak of another site because like most people you re-use passwords, then I only have one factor. It still provides a fair bit of security because of that.