Believe it or not, "apps" are an important "feature" of a smartphone, even if it's not theoretically bundled with it. Moreover it's not just banking apps, those are just the first ones to go, but any that don't keep backend compatibility will eventually break.

The entire point of the cellphone is that third party apps are required to live a modern life. If I cannot run the apps required to pay for a parking spot or perform a 2FA ritual then there’s really no point in even having a phone. The first party software isn’t compelling enough to justify the pocket space.