Right now, when someone leaves, the role forgets.
Picture every role in your organisation as a seat. Someone fills it for a few years — learns what works, what to never repeat, who to call in a crisis. Then they leave.
The seat is empty. A new person arrives. They have a job description and a wiki nobody updated. They make the same three mistakes their predecessor made two years ago. They wonder why this is so hard.
Every time someone walks out the door, the role resets to zero.