For example: Just two nights ago, a crazy homeless man tried to assault me with cinder blocks. Had I not been able to outrun him, I'd certainly be in the hospital. I called the cops, but by the time they arrived, the man had taken off on bicycle. The police couldn't find him. He'll likely victimize quite a few more people before he's caught.
Last week, an intoxicated driver hit a parked car in front of my home and drove off. Cops couldn't track the car. The driver is still out there and still a danger to others.
On a bike ride a couple months ago, a driver got behind me in the bike lane and yelled that he would run me over. Again, no arrest.
The likelihood of being caught is incredibly low, and antisocial people know this. Better surveillance of public areas would increase the chance of arrest and discourage such psychopathic behavior. I'm having a really hard time imagining a scenario in which this cure is worse than the disease. It is other civilians who endanger my life on a monthly basis, not police.