>I like New York a lot, but this sort of small talk with strangers is absolutely something I miss.
It's not about blocking the flow of traffic. It's about not invading the (already small) personal space of others. I think the appropriate term is "etiquette."
As I said, there are absolutely appropriate situations in NYC to engage with others. It's just that those situations are different from those that are appropriate in other places.
As someone who was born and raised in NYC (and who lives here again), that's normal to me.
As someone who's lived in a dozen other places all over the US, those situations are different in many places.
In a walkable small town, it's normal to (at a minimum) nod in acknowledgement of those you pass by on the street. In NYC, when you pass by a couple hundred people in the space of a couple blocks, if you tried to do that you'd end up with whiplash.
In places where everyone is in their car unless they're at the place they wish to go, it's not unusual to interact with folks at those places. But you certainly wouldn't roll down your window and say hello every time you encountered another car.
That just doesn't happen in New York. Maybe that's due to space constraints, but it's not like I'm blocking the flow of traffic more or less when I talk to someone on a bus.
I like New York a lot, but this sort of small talk with strangers is absolutely something I miss.