XDR vs SIEM: When should we consider migrating?

We're currently using a traditional SIEM solution (Splunk) and evaluating whether to migrate to an XDR platform. Our security team is split on this decision. Current SIEM setup: - Splunk Enterprise Security - ~200GB/day log ingestion - 5 security analysts - Integration with 15+ security tools XDR considerations: - Promised better detection and response capabilities - Reduced complexity - Higher costs - Vendor lock-in concerns What are the key decision factors? When does it make sense to migrate from SIEM to XDR? Can they coexist?