Plus with all the people around, they’re not really scared of humans. These aren’t the roaches in movies that scatter when a light comes on or they see a person. They’re used to us by now.
I’m picturing a dark alley late at night. A human opens a door, and the light from inside spills out on the ground just outside. Right there, an enormous cockroach grimaces slightly from the sudden light, takes a drag on a tiny cigarette and nods hello at the human.