As with all interests or genres, everyone has a different experience. But....

1 - they're telling about human nature 2 - cautionary tales, one can learn a lot about protecting themselves by learning basic commonalities of past crimes. A major lesson, IMO, is how girls are often conditioned to value manners / politeness over their instinct but that's to their detriment. 3 - personally, I was a young teen when a friend was murdered and then peripherally knew a few women that were victims of what was believed to be a serial offender. These events were all during formative years and tackling fears meant learning as much as one could. The murdered friend ended up as a case being unsolved for many years, so there was little real info in her case but much to learn from the global community.