In addition to the above benefits, I would add that setting term limits avoids founder's syndrome - particularly when implemented at the time of agency formation. However, this is likely a primary reason why a surprising number of nonprofit boards do not establish term limits on board member years of service.* From a BoardSource posting on a nonprofit accounting site:
Term limits may seem threatening to founders. A founder often has limitless devotion and attachment to the organization and easily becomes fearful of losing control.