Earlier quoted context omitted.
"The problem is that only a tiny percentage of harassers and rapists are ever convicted." How can that be known? Why do you presume that someone is a harasser or rapist if they weren't convicted?
Less than 1% of rapes lead to felony convictions: https://www.washingtonpost.com/business/2018/10/06/less-than... Same article notes that between 2-8% of rape complaints are false. Worries about false rape claims are wildly overblown.
If an accusation only has effect if it's proven in court, there will be few of them.
If you can destroy someone's life by a mere accusation, false accusations will be very common. Also, just a threat of such an accusation will be very powerful.