Defender for Cloud depends on the Log Analytics agent.
Use the Log Analytics agent if you need to:
* Collect logs and performance data from Azure virtual machines or hybrid machines hosted outside of Azure
* Etc.
Reference:
https://docs.microsoft.com/en-us/azure/defender-for-cloud/os-coverage
https://docs.microsoft.com/en-us/azure/azure-monitor/agents/agents-overview#log-analytics-agent