Going to the Toilet is a Tactic
Imagine you are taking an exam—a very long exam, let’s say it is three hours—and you are stuck in a part of the test and cannot pursue further; you just cannot solve anymore questions or problems. If you are allowed, you have to go to the toilet. The main thing about going to the toilet is that, even if you are not going to use it, you will walk to and from the toilet, giving you plenty of time to stretch your legs, arms, and whatever. I believe that this allows you to clear your mind of the stress of the exam by simply walking.
If you can go to the toilet, you must at least go to the toilet once, and if you are allowed to go unlimited times, you must go if you are even slightly stuck on a problem, but do not overuse your right to go to the toilet too much, because then the benefits of it might not be that much compared to the time it takes to go to and from the toilet.
Therefore, going to the toilet is a strategy in many situations, so if you can, you should do it.