In post-Soviet countries there is a concept of non-religious "palaces of culture", which also lost their ideological content and just host arts and crafts now. Albeit, they are less useful for just hanging out than they could be. Also, libraries.
Religious spaces have some extra spice, as does the local mall where middle schoolers do random shoplifting to be edgy.
This kind of stuff just won't happen if you have to drive to your local park. Cars and car-centric city design is a huge, huge part of the problem and lack of third spaces in my opinion.
"Car centric urban design" is the catch all ill and if we just fixed transit it would go away.
Except it won't, because all the social factors that make car centric urban design preferable will still be there.
But even compared to NYC the proliferation of parks and playgrounds is astounding. We thought we must live in a green paradise, but it really doesn't even rate (something like 14% tree cover; most major EU cities are > 20%).
I think stuff like this is changing. You're starting to see far less car-centric design, and there are little programs like NYC's request a tree. I worry a little about what self-driving cars will do the trend though, but maybe it's not a big deal?
I think it's just an issue of community. Like, evidently our community likes having nice stuff our kids can use.
Also it depends of city strategy> having marginalized only buildings/areas is a bad idea, that's why in states like baltics, social apartments(the new ones) are not separate full buildings, but just apartments spread evenly across the city, contributing to diluting concentration of marginalized people in one spot and 'social control' keeps these regions safe