Social aspects in the sense of that we nowadays use them for cars only. Back in the days people traded on streets, had cafes and social interactions. Kids could play football and learn how to cycle. That's all used up by cars with all the externalities that comes with it such as dirt, noise, wasted space, deaths by accidents and air pollution.

Not to forget: streets were used that way until ~80 years ago. We just can't remember them any different any more.