And in a public transport-dominant society every neighbor is also someone in your way, taking up a spot at the restaurant you walk to, filling up the subway train and therefore making you late in your commute…
There’s no free lunch. Doesn’t matter where you are, more people = more crowds.
Humans are pack animals, not flock or herd. I think going beyond the Dunbar number is possibly the thing making people grumpy in highly dense areas. If people cannot know those around them in a meaningful way, do they even view them as human?