Two things: first they’re a bank, in the Uk, it looks terrible to not have a banking license and that’d kill their IPO price. Second, there are limitations on customer deposits and the services they can provide because they aren’t a bank, for example they aren’t currently Uk equivalent of FDIC insured. There’s basically an assumption that their banking license will massively help both their growth and their value per customer.
But they do have a license in Lithuania which means all the deposits are covered by their insurance. I agree about the IPO part but I really find it hard to imagine an IPO would make any sense for them at this point. I don’t think there is any chance they could reach their current private valuation…