You might be overthinking it. Most people want to use their phone for convenience, and if an app allows them to remove just one step in their banking activities, they'll probably do that.
As for the second part (separate authentication methods), sure, would be rather problematic if they require you to have a phone, but that's a completely separate and different issue.
As for the second part (separate authentication methods), sure, would be rather problematic if they require you to have a phone, but that's a completely separate and different issue.