All the child safety things you cite, they are risk mitigation, they don't save all lives per se - kids still get killed every day in car accidents, kids still incur brain injuries while biking with or without a helmet. A kid in a belted car seat is far more likely to survive a collision than one who is not, that's a fact - so use a car seat. And I can recommend that people wear knee and elbow pads while roller skating, its darmn hard to crack your elbow with them on than without them - take it from me on that simple one.

The nanny state may be whatever it is, but the world we live in now is far different than the world we grew up in - traffic is much, much thicker than it was in the 60s, when traffic moves relative speeds are up, and drivers are far more distracted today than they ever where back when. I have a fond memory from childhood, coming back from the doctor's, stopping at Jack in the Box for a burger treat, pulling out of the lot, a few moments later my mom stopped my body from hitting the windshield when the car ahead of us stopped abruptly. I can still remember the sensation of rising out of my seat, and being held back by mom's arm flung out to protect me. It seems like Mom's can always do that move, but we were traveling at probably less than 30 mph, her arm would be dislocated at 45 mph and worse would happen at a higher speed. Point being, environments change, kids will fly through windshields at high speeds in all generations, better technology comes along for personal protection,so use them.