As the grandparent poster just said, it’s the spread that means this might work.
Say a current bank gives you 0.1% interest on your deposit and loans that money out at 4.5%. A new bank could pay 2% interest to the depositor and loan the money out at 3.5%. Thus the depositor gets 20x more interest, and the lender pays less.
Say a current bank gives you 0.1% interest on your deposit and loans that money out at 4.5%. A new bank could pay 2% interest to the depositor and loan the money out at 3.5%. Thus the depositor gets 20x more interest, and the lender pays less.