However, Beit Hillel allows bringing even burnt offerings on Holiday. What is their logic? The Torah said, "You will celebrate to God." Whatever sacrifices are needed, you will bring them. It has nothing to do with the permission to cook on Holiday.
This seems like a simple disagreement. It becomes complicated because each view changes to which of the three Holidays it is applicable, before the Holiday or after, and so on.
Art: Young Woman in the Kitchen by Andres Commodi