Why do you use white sauce in Lasagna?

White sauce, or béchamel, is used in lasagna to add a creamy texture and rich flavor that complements the other layers. It helps to balance the acidity of the tomato sauce and enhances the overall moisture of the dish. Additionally, it contributes to a smooth mouthfeel and can create a deliciously gooey layer that binds the ingredients together, making each bite more satisfying.