Why does lee use the words useless sacrifice in his farewell address?

In his farewell address, Lee uses the term "useless sacrifice" to emphasize the futility of continuing to fight in a losing battle. He acknowledges the immense losses endured by both sides during the conflict and suggests that further resistance would only lead to more suffering without any meaningful gain. This phrase reflects a desire for reconciliation and peace, highlighting the need to move forward rather than dwell on past sacrifices.