These questions are really only useful for impulse purchases, not needed purchases. In which case they can be useful. I’ve definitely saved money waiting a day or two to actually buy the clothing in my online shopping cart.
Also, the food question is ridiculous. There is no way to be 100% sure that you’re going to eat something (particularly if it’s perishable). “Is it probable that you will eat this food given the amount of time you will be home before it will spoil?” is a better question.