My family grew up in communist Poland. In the kind of neighborhood with those ugly grey buildings.

Well, say what you want, but the communists knew how to build neighborhoods.

Between all buildings there was always a 30-50+ meters green space with benches, places for kids to play, walkways, etc.

I remember in the early 90s how lively and safe it was. People spent a lot of time of the day outside. Grandmas had their benches, looked the kids, play, adults would gather and have a drink, etc.

Today? It has all been swallowed by cars. As progress and money came the entire neighborhood has been swallowed by cars. Kids are confined in a single area. You rarely see people outside. People sit at home.

For reference, this is my old neighborhood, albeit the street view is a decade+ old (half the areas are from 2013 because since then entrances to cars have been gated and are only for private cars), but if you stretch the imagination and try to put people around and benches and kids playing areas you can get the sense:

https://www.google.it/maps/place/Osiedle+Kopernika/@49.81596...