I think this varies quite a lot from one location to another. I grew up in an impoverished town in the US south. When I was a kid if your car broke down, a stranger would stop to at least give you a ride or possibly even try to repair it on the spot. If you so much as threatened a woman in public you could expect to have a number of men immediately step in to confront you.

Many year later in life I lived in Manhattan, where you could literally have a frail old lady being beat up in front of a crowd of grown men and everyone would either pretend they didn't see anything or at most pull out their phones to record it.

I don't know what my old town is like today, but a few years ago I was on a bus in Latin America far from any large cities and a pickpocket robbed someone, the passengers on the bus seized the guy, beat him up, striped him naked, and the bus driver slowed down and opened the door while they shoved him out onto the curb.