Some of those warnings and disclaimers are mandated by law, and so the manufacturers dare not deviate from the prescribed wording, even if it seems silly under the circumstances.

For example, the law says that if there is a picture on the package, and the picture includes some kind of food that isn't actually in the package, the picture must be labeled "SERVING SUGGESTION." For example, on a cereal box, if the picture shows cereal with milk, and there is no milk in the package. That seems silly—who would expect to find milk in a cereal box? Or who needs to be told to put milk on their cereal?

But suppose the picture showed cereal with raisins, and there weren't any raisins—you'd feel cheated, wouldn't you? That's the kind of situation the law was meant for.