Yes, my experience in the suburbs is that most residents hop in their cars and take off somewhere with their tinted windows rolled up, and there are no "third places" around to casually encounter your neighbours. Sometimes there will be yard sales, BBQs, or birthday parties though.
But my experience in an urban apartment building is not very different. You might encounter someone in the elevator but it's polite to keep quiet. A lot of dense townhouse neighbourhoods are built without any corner stores, cafes, or bakeries mixed in at the ground floor.
I like that this family found a way to make do without any third place at all, just occupying the sidewalk and roadside. But I'm sure it would be a lot more comfortable if they had at least a shady patch of grass!