When a number is assigned to a user than there is an option or even toggle to make it so that all of their individual outbound calls and text messages are coming from their assigned number and not just the default number. Then if you have someone calling from lead gen or lead management, they have their own unique number and when the closer calls it calls from their number. That way if the person calls back then it goes directly to that user.
Every other dialer I've seen operates this way. But for some reason support explained to me that it all just goes outbound from the default number.