The machine knows what should be in a certain dish and notifies you if something else is in it.
Human food tasters are really easy to get around.
I know nothing about these devices, but I’m seriously doubting they easily cover all kinds of food AND all types of chemicals and viruses and bacteria, much less fast.
They should have that in hospitals, then. Maybe cut down on the waits for “what might have been poisoning/sickening patient”.