There's a middle-ground between a big city and full countryside.
I lived my childhood in a place with about 4000 people in it. School, friends and everything else I needed was within walking, or at least biking distance. My parents didn't have to drive me everywhere. Obviously there weren't as many possible hobbies and events as in big cities, but mobility wasn't an issue.
Smaller cities with about 40k-200k inhabitants can also be a nice sweet spot: big enough to have a decent number of events and hobby opportunities, small enough that you have low-traffic sidestreets within walking distance of the city center, and nature is still very much in reach
Assuming a European city layout where a city center exists and the 200k inhabitants aren't all spread out into suburban sprawl. Suburbia quickly kills the idea of walking and biking distances
Likewise. All my friends were within cycling distance and we had nature to play in. Personally I can't imagine growing up in a city like London.
Right. Most people in "rural" places live in small towns. My wife went to high school in a rural Iowa town with 2,000 people. You can walk from the high school to anywhere in town in 30 minutes.