I grew up in Paris and that’s where I’m raising my son right now. I think there couldn’t be a kid-friendlier place (other than cost):

- I can walk to a gigantic park with many playgrounds in 5 minutes - I can walk to a small little park with a few swings and a slide in 1 minute - I can walk to a pool in 15 minutes - I can walk to my son’s future kindergarten and elementary school in 2 minutes - I can take public transportation to a gigantic zoo in a bit over 30 minutes (also a gigantic aquarium, playgrounds, etc. in the same area) - I can take public transportation to a world-class kid science museum in under 30 minutes (also a kid-centered movie theater, indoor skydiving, bowling, many more play areas, etc. in the same spot) - I can take public transportation to an amusement park in 45 minutes (1h to a second one, Disneyland Paris) - There are tons of indoor play areas for days it rains I can walk to or take public transportation - I have pediatrician and world-class pediatric hospitals walking distance, or a 5 minute wait away for EMS

And all of that much more safely than if I had to drive my kid everywhere (leading cause of death from 4 year onward IIRC. Once my son is old enough, he'll also be able to independently go to all that (say when he’s 12), which would be completely impossible in suburbia.

The only thing you can do in the suburbs is try to privatize all these resources, which is what a backyard is more-or-less (and a private pool, a home theater, buying tons of toys, etc.), but you inevitably get lesser versions as a result.