Some guy will post a picture of a pretty standard looking pepperoni pizza and say: "Imagine not living in new york." And then there's the whole bodega discourse, which is also funny. "For you non-new yorkers, let me explain: a bodega is not a corner store. It's a place where you can buy gatorade, toilet paper, AND eggs." Thank you sir for explaining that to a slack-jawed yokel such as myself.
Compared to overcrowded and underdeveloped large cities like Manila or Jakarta? Sure.
Compared to other major "rich" cities? I'm struggling to think of as dirty as NYC. I hear Rome is pretty bad but haven't been there.
I think the point is that NYC is the richest city on Earth by some metrics and still can't get its shit together. It's a microcosm of America as a whole.