Group Health insurance will improve who decides to work for you or stay with you long-term. When employees leave, retraining new employees can be costly and easily reduced by simply retaining employees.
Many employers will simply give someone a raise, but studies show that dollar-for-dollar employees prefer employer benefits and rethink leaving jobs with a benefits package in place.
A strong reason for group health is to spread the risk and cost among all employees. In most cases, the insurance is still less expensive for everyone when compared to getting insurance on their own.