Its easy for people to cope if the winning side also had more manpower, better weapons, better logistics, and communication (union had far more factories, more people, more rail networks, and a complete telegram network back to the White House. the losers did not).
But in my opinion, that is nothing but cope. A good general should realize that they have no chance to achieve victory and instead seek an alternative route, either through diplomacy or an insurgency, not draw out the inevitable and waste lives for nothing.
Related: The Civil War is extremely formative to the US approach to war in a way that went away from the European established approach (decisive battles convincing one side to give up). The US model was broadly "deny all alternatives to surrender", a model developed by the Sherman/Grant "total war".