Re: A realisation of what they are
"IT companies with banking licences" is only true so far, because banks still make their money on the balance sheet, by lending for more than the loaned capital costs them.
The point is valid that IT is absolutely central to any large customer service outfit or transaction processor, but it's not usually what makes them money - although done badly it usually loses them money. If you look at energy suppliers they might seem to be "IT companies with an energy supply licence", but again, poor IT loses them money, good IT doesn't make them more money.
I think the definition of an IT company is that they intend to make money from either selling software (outright or SaaS) or from data processing.
"And that to outsource your core function should make you question why you exist?"
That is true, but I think that banks (energy suppliers etc) all still see their IT assets as a big, complex, ugly, expensive cost that they don't understand - and don't want to understand. They outsource it not really to save money (made up business cases notwithstanding) but because they don't want to get their hands dirty.