Harsh punishments, as a deterrent against crime, don’t work.
People that commit crimes do not generally consider what the punishment is, because they do not anticipate getting caught. They generally think they will get away with it. So it won’t matter what the punishment is, they will still think they won’t get caught.
If the punishment for jaywalking was death, people would still jaywalk, but they would only do it when and where they think they won’t get caught.