Whey is food by-product, not food. Egg whites are still food.
Main difference between those two would be riboflavin b vitamins a little potassium and magnesium in the whites. While the whey would actually contain more bcaa. If u are adding in a multi u would be hard pressed to notice any shit of a difference. If u want to debate whole foods total vitamin and mineral content along with omega 3s etc then u would be in essence correctly whole foods would be stellar. I see where u are coming from. There are plenty of variables to consider.