I don't have kids either, but I'm in touch with my nephews (ages 7-14), and get to see how they're growing up. It's a very weird mix of culture change, everyone's being on their phones 24/7, and not walkable streets for kids. Luckily they live in NYC, and eldest one is now allowed to subway around, go to places as long as he follows the general guidelines set by my sister. That being said, he tells me how nobody else in his class is allowed to do the same, and their parents basically take them everywhere. At the end of the day, he still goes and plays Fortnite with his online friends anyways though.

It is definitely different from my childhood where even as an 8 year old I remember going to school by myself, hanging out in the neighbourhood with friends and etc. Definitely wouldn't blame it on just one thing, as every complex problem, it has multiple contributors.