That was the key economic function about a hundred years ago. Since 2006 or so, their key economic function seems to be transforming shit loans into AAA-rated investments and selling them to suckers, then getting bailed out by the government. That’s not an improvement. They can still offer loans, but they should either borrow that money from the government at the overnight rate (if deposit accounts are nationalized) or use their own capital. That way, they are more likely to be accountable for the quality of their business.