Actually, I live in a very low crime small town. If I lived in a high-crime area, I wouldn’t invest in bars on the windows and unbreakable doors. I’d invest in leaving that place, ASAP. It’s not as if those ruffians magically disappear when you open your door. Remember, when seconds count, the police are only minutes away.
I certainly wouldn’t try to put out a large fire with a hand-held fire extinguisher, but I could probably prevent a stove-top fire from burning the place down.
I also wouldn’t try to take out a gang of professional criminals with a shotgun or a handgun. But I could probably stop a thug who broke into my apartment late at night. I’d rather have a fighting chance than trust it to leave with just my stuff.