I think the use of screen protector or guard has always been a thing of choice. Regardless of how tough the screen protector to your device is, you can either opt for one, perhaps, you want to have your device protected against unforseen destructive incidences, or you can choose to let it be as you bought it.
But the risks involve in not protecting one's smartphone screen could be very detrimental. Apparently, there are so many cases where our smartphone get caught up in accidental occurence, and the only thing that keeps its screen from being damaged is the protector.
For instant, let's say your phone falls from great height, the only thing left to have it prevented against complete wreckage would be its screen protector. The reason why its screen protector is so vital is because the screen of every smartphone is the first point of contact if anything happens to it.