The cost of the robot is less expensive. Robots don't take breaks. They work in 12 hour shifts. They don't need uniforms. They don't sleep or get tired. They don't take sick, vacation, or personal leave. They don't need health, dental, vision, disability, or life insurance. You don't pay employer taxes or FICA on bots. They don't need workers comp insurance. They don't need training.
Etc etc etc