A couple reasons to put your configurations in version control:

1.) History of configurations and configuration changes. This, along with event forwarding (and event auditing), will provide a solid foundation to determine root causes of failures and the configurations that caused or facilitated these failures.

2.) Accountability. If admins put their configuration changes in Git, someone can use Git Blame after a failure to determine the actor who changed the configuration, which caused the failure.

3.) Ease of deployment. Using git along with a build server enables your organization to create deployment configurations to instantly deploy both production and staging infrastructure and configurations.

Not all Windows configurations can be placed into version control, but reports on configurations can be created (like GPO reports, AD reporting on objects in OUs, etc) and placed into version control on an automated basis to at least catalogue configurations on a regular interval.

Good luck!