Just a quick YouTube search. I’m a life long long New Yorker, I can promise you that’s not the busiest. I can try to find you some video of the 7 line, it’s like that all the way from Grand Central to Main Street Flushing during rush hour.
The thing about the subway is that we all try to hold onto a pole or bar, total vectors for the spread. It’s not just an obvious case of being near each other, we’re forced to touch the same surfaces so we don’t collide every 30 seconds.