In addition, no, it's not to look cool. From an article I saw, "Interestingly, in many European countries, suppressors on firearms are mandatory to make target shooting and hunting quieter and less disturbing to neighbors. Firearm owners in France, for example, are fined and penalized for firing guns without a suppressor to quiet the noise." I didn't fact check this claim, however.
As with all things firearms related, it's best to model France.