I just wanted to echo your experiences growing up in a suburb with lots of single-family houses. Even though we were in different classes (slightly different ages) there were loads of kids in the blocks around my house. We'd play games in the green belt (utility corridor) or at the park in the middle or meet up for swimming in the community pool in the summer time. I'd walk or ride my bike to friend's houses all the time to play their Nintendo and they'd come over to my place to play my Sega. You don't need to live in a dense city with massive apartment complexes to have neighborhood friends.

And yeah, I definitely had friends that I mostly only saw during activities (sports, band, scouts, etc.) they were still good and close friends. Spending over a decade of at least one night a week together tends to make people pretty close.