What happens to the food is likely repeated on every cruise ship in the world, at every buffet, in every casino or hotel, etc. After sitting about 4 hours, all the food is deemed inedible and responsible companies discard it.
I've seen this question often on these Forums, but not once have I read a post in which the writer suggests she would volunteer to eat the food or feed it to her own family if she worked at one of these establishments.
I've had food poisoning once in my long life - most likely from eating the last shrimp on a picnic platter. Let me say now - I wouldn't touch that display food or feed it to anyone else!