Have you ever looked at the accounts of women who /have/ reported it? If it actually goes to trial basically the defense finds every single thing you ever did and tries to portray you as a slut who was asking for it. If the person is famous people will say you’re lying and trying to get rich out of a settlement. You’re required to repeatedly go over every step of the assault whether it was harassment or rape. They ask if you orgasmed (because that means you wanted it), that your jeans were too tight for a rapist to remove them, you were partially responsible because you passed out (so it wasn’t rape), ...
Then even if they do get found guilty they punishment may be insignificant (think Stanford rapist)
And then there’s how you get penalized, irrespective of whether the person was found guilty
* if you’re on social media you get harassed by the bigots on chan, Reddit, etc
your name on google ends up publicizing the assault
* if the person you’re accusing has power/influence you lose your career (which is why so many victims in film didn’t say anything about asshole guy). Tech has a similar problem - look at what happens to women who call out anything at tech conferences.
The result of saying anything is typically catastrophic to the victim and frequently has little impact on the abuser.
If you ever actually pay attention you can find out about the people women tell each other to avoid at cons or parties because they are known predators. Because doing it that way is less harmful or and damaging to your own life than going public.