From my understanding it doesn't have to be "for the lender" and I'm not understanding your second point.
לא אסרה תורה אלא רבית הבאה מלוה למלוה
It doesn't seem that they charge more because not getting the funds on the spot like cash, rather just to cover their fees. I'm no rabbi of course.
Either way I'm just passing on what I've heard not my psak.
I was just questioning the premise.