A paper in Law and Management by J.S. Nelson explores the support for [strong] corporate governance as a competitive advantage.

On the internal front, strong corporate governance procedures are presumed to check and control agency costs…On the external front, good corporate governance procedures are presumed to enhance the strategic direction of the firm, resulting in better engagement with its stakeholders and more long- term financially rewarding behavior.

The paper lists six competitive links: trust, commitment, key personnel, better communication with stakeholders, better planning for the future/sustainable development, and synthesis of procedures and values. In other words: minimizing agency costs.