A Screen protector that protects your display from scratches, scuffs and damage is ‘unnecessary crap’? I think there would be millions of iPhone users that would disagree with your assertion. There is a lot of money to be made either way from watch bands as a direct accessory to the Watch, as a screen protector is for the iPhone.
If the phone drops on its weak point, no screen protector will stop the screen from going pop. Seen 100s shattered with protectors.
You also have to go out of your way to try and scratch a modern smart phone display, so the only people who are thankful are the people who don't look after their stuff properly.