The customer wants to automatically route cases based on language skills and expertise.

Skill-Based Routing is the feature that best facilitates the automatic routing of cases based on language skills and expertise. This feature allows the contact center system to match incoming cases with agents who have the specific skills and expertise needed to handle those cases effectively. By ensuring that cases are directed to the most appropriately skilled agents, skill-based routing enhances efficiency, improves resolution times, and increases customer satisfaction.

References: https://help.salesforce.com/articleView?id=sf.omnichannel_skills_based_routing_setup.htm