A very similar article on the Financial Times regarding this all. Some funny comments on the article too, this is my favorite.
"The way that the likes of Monzo and Revolut work is to make some loss leading offers particularly in the area of overseas spending, cash access. and international money transfer They thereby attract a profit free customer base and start boasting about account numbers.
Next step - they get some suckers (sorry backers) to pony up a large pile of money for them to spend on ping pong tables and bean bags and ongoing account manintenance
Next step… they start to pull back on some of the too good to be true offers as it becomes apparent that the business model isn’t driving any revenue.and is driving a lot of cost."