Automating the Site Reliability Guardian (SRG) to trigger with AWS tag changes, particularly on Amazon EC2 instances, can significantly enhance efficiency, compliance, and cost optimization in large-scale AWS environments. By using a step-by-step setup involving API tokens, Amazon EventBridge, and Dynatrace, teams can automate the monitoring and management of resources, ensuring critical policies are applied consistently and enabling proactive reliability measures. This process eliminates the need for manual intervention, allowing DevOps or site reliability engineering teams to focus on more strategic tasks. The guide also emphasizes the importance of testing and validating the setup to ensure seamless integration and the successful execution of guardian processes, ultimately contributing to a more robust and cost-effective site reliability framework.