Also, we generally know about all this stuff, like even if we don't have personal experience of violence we're well aware of the possibility. And carrying a knife might help, or it might make things worse if you're not experienced in using it to fight, but it's got nothing on getting together with your friends and making things hell for the people in power, or replacing them with better people.
Tangent about self-defence spoilered for being a bit tangent-y:
spoiler:I will say that personally I have been down the self-defence route, and it's served me well. It's the reason a creepy bus stop guy wasn't able to kiss me on the mouth (though I didn't manage to stop him getting my face), and I was able to break his grip - his arm would have been next if he hadn't backed away after that. The thing is, it probably wouldn't have worked so well against an armed or well-trained man, and perhaps even against a very strong one. And to women who wouldn't be able to fight back as effectively on account of disability or medical stuff or age, most men are very strong, so it doesn't work as a systemic solution*. There's definitely a part of me that wants a world where men are too afraid to commit sexual violence because they know there's a solid chance they'll get the shit beaten out of them if they try, but we shouldn't have to learn to fight just to be safe.
All that said, there is value in learning martial arts, but in my experience the main benefit is the self-confidence it can give you, both in terms of standing up for yourself and (more importantly) in having the confidence to intervene when a guy is creeping on someone else (ideally before it comes to the point of physical violence).
* Also most sexual violence isn't from strangers on the street, it's from partners and relatives and friends and bosses and priests and other people you already know.
Anyway, this US situation is properly fucked up. It's a symptom of a society with a serious misogyny problem, a broken political system, and a politicised supreme court. I hope this is the tipping point that properly sets off a fourth wave of feminism, because we sure as fuck need that right now.