Besides PIN code screens, which I've already written about not understanding their purpose, there's one more such feature, but a bit smaller. I'm talking about when from the main app screen you try to go back, and the app double-checks with you if you're sure or not. And literally all banking apps and some other quite random ones suffer from this.
The funniest thing is that it also aged poorly. For example, Tinkoff shows a toast "press again", despite the fact that for about five years everyone's had gesture navigation in their phones. Some show alerts, which looks a bit better, but even more blocks me from the action I want to perform, you need to find a button on the screen that will let me out.
I suspect this is a way to protect from grandmas non-advanced audience, so they don't accidentally exit the app. But I'm not sure this helps more than it annoys others. People just get used to minimizing instead or unloading the app by system means.