Chicken and egg problem. Crime highly correlates with poverty. People perceive transit as being a poor people thing because it’s cheap. Only poor people take transit. You get the gist.
Also, the incidence rate is probably lower than people’s perception. I lived in San Francisco for about 3 years and only experienced one incident while taking transit everyday. Of course, transit doesn’t have the problem mentioned above, so maybe it’s not the best example.
I tried taking transit a couple of times in LA and in my hometown in a suburb in Florida. Transit is underutilized in these places (read as, people see it as a poor person thing). It was surprisingly… uninteresting. It was just getting from A-to-B. People mostly just sat on their phones or stared out the window or chatted. Was quite nice.
So maybe grab a friend or two for safety, since you’re concerned about that, and give it a shot. I think you’ll be surprised.
But if you’re in LA or New York, the trains are super dirty. So uh, i recommend not one of those. No idea where you’re located
(Edit: I’m assuming you’re in the US because that kind of opinion is quite common there.)