I really don’t see where are the short or long term savings for them
Short term: customers are pissed. The only reason they still had a 30 euro per month Intesa San Paolo bank account was that changing the IBAN everywhere is an hassle. ING direct gives the same stuff for free but the thought of the many forms and calls to change it, let them stay hooked. Now they got a new IBAN. Also, no more physical bank access. They lost the only reason to stick with them. Can move to ING and get the same but for 360 euro less each year.
Long term: customers migrated somewhere else and pay the fees to the competition