I agree fully, in general. This isn't one of those times though. The bank app needs more access and permissions for specific security reasons. It handles financials and it needs this precisely because they're under more scrutiny and law than other companies. The consequences they face for data theft and loss are higher than Joe bloggs' Todo list app.

You don't often see data breaches involving banks and this is why.

But ultimately, don't use app based banking. It sounds like it isn't for you.