Managing AWS IAM using Terraform offers numerous benefits, including automation, consistency, repeatability, and versioning of IAM policies and role management. It allows for audit trails, least privileges, and multi-factor authentication, making it a crucial component of Zero-Trust security. Terraform enables the creation of dynamic IAM policies, cross-account access, and policy-as-code, ensuring that security controls are consistently applied across an organization's cloud infrastructure. By enforcing IAM best practices with tools like Checkov, organizations can preempt configuration errors and security risks, while integrating IAM governance and compliance methods to ensure alignment with regulatory standards and security best practices.