The way the App is designed in terms of functionality,...

The way the App is designed in terms of functionality, appearance and user experience will decide how much money it will generate.
Of course PIL (and all of us) want the user to interact as much as possible. The full bandwidth of her/his finances over the years to come in a single App.

.....from when they receive a payment in their first job as a teenager up to supporting family and an own business when they get older.
I agree with Mike. Its is about keeping the customer for a long time and having them to using as many services as possible.