Using the functionality for roles and responsibilities you can clearly communicate and manage

• Which people hold which roles and the state of the individual role assignments
• Which responsibilities a particular role entails
• How often responsibilies are expected to be addressed and actually set aside time to address them
• Insight relevant for managing each responsibility in accordance with expectations and best practices
• Which responsibilities are unmanaged

Roles are intended to function as living, up-to-date job descriptions which gradually evolve as the role holder and organization in general learns more about what the responsibilities should entail and how to operationalize them.

By making proactive use of the role functionality, roles and responsibilities are easily redistributable as the organization grows and adapts.

Here's an example of how a role might appear: