Um...no. The goalposts have always been that the purpose of the brainteasers was to demonstrate reasoning skills. Using Fermi estimation is demonstrating reason

Um...no. The goalposts have always been that the purpose of the brainteasers was to demonstrate reasoning skills. Using Fermi estimation is demonstrating reasoning skills. It's not like some trick that you have to know, it's not a formula. It's something any intelligent person would do on their own when faced with a task of this sort.