Idk if it’s fair to say that there’s barely any crime to crack down on (maybe it is?) but your second point is definitely an issue. Whenever I actually encounter someone who seems dangerous (eg pacing the platform yelling in people’s faces about how he’s going to kill all the [insert various racial/ethnic/religious slurs], there are never any cops around, it’s hard to call 911 or something with the person standing right there flipping their shit, I don’t know what I would say if I did call (“there’s an angry racist down at 34th st but he’s not saying anything to me personally and he hasn’t actually done anything to anyone yet”?), and by the time I could go and get someone in the station, the train would come and everyone involved would be long gone. I’m also always concerned about getting the police involved and somehow making the whole situation worse.