So why have crimes at all? If someone steals from you, or assaults you, you can always sue. The thing is, that shouldn't be the victim's responsibility.

You're acting like libel just became a problem in the last 5 years. There are good reasons why we don't really have criminal defamation prosecutions anymore. They always involve tons of disputed facts, and they require tons of resources to investigate. Choice of cases is always political.

Let me tell you who is a good candidate for a "cyberstalking" charge. You maintain a database of police involved in questionable shootings. When one of them gets canned from their present department, you track the new PD they're foisted onto, and make sure to let the local BLM chapter know about the bad apple they're about to get, and a lurid description of what you think their crimes are. Why, that sounds worthy of some prosecutorial resources (election year, after all). Aren't you glad you made being mean on the internet a crime?

Get a fucking restraining order. It's ridiculously easy; too easy, in fact, to the point where they're routinely used as leverage in other civil disputes. Violation of restraining orders is a crime. This is a solved problem.