They are multiple reason why it is better to leave AC on. But it really depends on the house. One main reason is that when AC is off is that humidity increases

They are multiple reason why it is better to leave AC on. But it really depends on the house. One main reason is that when AC is off is that humidity increases which causes cooling harder. This is because the cooling process of an AC unit involves removing humidity from the air as well as heat. When the air is humid, the AC unit has to work harder to remove the excess moisture from the air, which can decrease its overall cooling efficiency. The other reason is that house and furniture will store heat and then cooling will get harder. Also AC runs more efficiently if its constant.