Here the plastic tool isn’t meant as a guide for you to apply the screen protector. Instead it’s holding the screen protector ...
Even the liquid screen protectors have their issues ... first decade of iPhones and is still used in most Samsung phones. Gorilla Glass is stronger than most glass, but it wasn’t great ...
But still, that's impressive durability with no screen protector. However, the iPhone's Ceramic Shield glass isn't invincible. If there's one person who treats their electronics worse than I do ...