Ever since I started baking, I have used only bananas as a substitute for eggs. Bananas definitely give the moist texture for cakes and breads, but the drawback is the flavor of bananas is dominant in those baked goods. So whatever changes you make otherwise in the recipe, the end product tastes the same. For example my carrot cake and zucchini bread tasted similar. It was definitely very good, but we need some change right!