I use some bank apps because they're quicker than the websites. But I do this with a cheap Nexus 7 tablet that stays at home with a label saying "full take" stuck to the top to remind me to not trust it with any sensitive information.
Segregating apps onto different devices is the way to go to protect yourself from corporate malware.
To easily check balances and make transfers wherever I am. This is possible without the app, but the app makes it easier/quicker than the mobile site in most cases.
> So that when you get mugged, it can turn into a kidnapping?
How do you suggest a mugger to find out whether such an app is even installed, let alone do anything about it, in this day and age of full-device encryption being the default? Even assuming a mugger somehow has access to the nation-state-level compute resources and exploit tools necessary to gain access to anything on my phone, by the time the mugger has finished using said tools and compute resources, I'll have already changed my passwords and invalidated existing login sessions.
Also, kidnapping involves considerably more effort and risk than mugging, so this is a weird argument in general. The vast majority of people with both smartphones and bank accounts almost certainly have banking apps installed on their phones, and I know of precisely zero cases of muggers deciding "oh you have a banking app? lemme go find my windowless van and kidnap you, drawing considerably more attention to me and giving you considerably more reason to violently defend yourself instead of cooperating; surely nothing will backfire from that, no siree!".
Muggers quite frankly don't give a flying fuck about the apps on your phone. They want your cash and/or whatever they can quickly fence.
> Segregating apps onto different devices is the way to go to protect yourself from corporate malware.
Having firmware that gives you fine-grained app permissions that you can freely grant/revoke also accomplishes this. If apps on the Play Store are subverting that, then banking apps are probably the least of your worries.
They make you do it, the same way they made you give them the device in the first place.
I don't know why anyone thinks it would turn into a kidnapping, but it's pretty easy for someone who has already forced you to give them your phone to use the same technique to force you to unlock it.
Same deal with home burglaries. No burglar in one's right mind is going to give the slightest iota of a rodent's anus about the possibility of there being a Bitcoin wallet and SSH keys on your laptop; most burglaries are smash-and-grab, and are intended specifically to minimize the amount of time spent inside the victim's home. Every second adds risk of complications; unless the burglar is targeting you specifically and knows ahead of time exactly which devices might have valuable data, it's in said burglar's best interests to take the laptop and run rather than spend precious seconds (or worse: minutes) "persuading" you to unlock it.
I just don't see this as enough of a risk to be concerned about it, maybe it depends on where you live.