The use case that is NOT a valid use case for leveraging the Oracle Cloud Infrastructure (OCI) Events service is "Capturing the OCI Monitoring service alarms and invoking autoscaling of compute instances." The OCI Events service is designed to provide event-driven architecture and enable automated responses to events occurring within the Oracle Cloud Infrastructure. It allows you to react to changes and activities happening within your OCI resources. The Events service can be used to trigger actions based on events like file uploads, resource changes, or task completions. However, capturing the OCI Monitoring service alarms and invoking autoscaling of compute instances is not a direct functionality provided by the OCI Events service. Autoscaling based on monitoring metrics is typically handled by the OCI Autoscaling service, which is specifically designed for that purpose. The OCI Monitoring service provides monitoring and alerting capabilities, while the Autoscaling service handles the dynamic scaling of compute instances based on predefined policies and thresholds.