Yes. If you don't measure, you will never know when the time complexity moves in your favor due to the constant, and other factors. For example, quicksort moves

Yes. If you don't measure, you will never know when the time complexity moves in your favor due to the constant, and other factors. For example, quicksort moves to a O(n^2) algorithm (insertion sort) for the last few iterations of a branch of work(typically n=1000) because this reduces the total sort time.