Additionally, as the world became safer and sanitized, we became more distanced from injury and it seems more traumatic. Parents are more afraid and focused on the downsides. As well as the fact that we have fewer kids than in the past. The potential consequences are greater.
It's also worth noting that the body and brain are anti-fragile. That is, they become stronger and more robust when challenged. Weaker in the absence of it. The end result of all this sanitization, safetyism and overprotection is a fragile human. One that is less able to cope with the challenges and messiness and nuance of the real world.
That negative feedback loop has led to quite a mess. The Coddling of the American Mind does an excellent deep dive on all this: https://www.amazon.com/Coddling-American-Mind-Intentions-Gen...
My sis used to climb out of her crib and flop down to the ground when she was little. Turns out she was just naturally athletic. Now she’s a personal trainer.
Put some pillows next to their bed and let them roll