As said, it is a bit fluid. If you just walk out into a crosswalk and get driven over then likely won't be any charges. If you enter a crosswalk reflecting all cars to stop, that is rather risky. If a car has time to stop but doesn't, the driver will be getting charged. Generally people wait for traffic to have a pause before they use a cross walk. In some really busy areas down town there will always be people waiting at a cross walk. Literally there would be near zero movement of automobile as you could spend an hour waiting for a crosswalk to clear.

Personally from a person that walks often, I rarely wait anytime to cross a street. Traffic flows a best it can but stops enough I can easily cross. At a controlled intersection in Canada you can wait two, there, four minutes till you get a walk for example. Waiting that long is very rare as you take your turn first chance you get.

For lack of better description, they put a higher expectation of personal responsibility. Someone walking should easily be able to tell when it is safe to do something and can easily change their path to ovoid an unsafe condition. They use this same logic in shipping and flying. The smaller vessel typically gives way to the larger less easy to maneuver vessel.