I really highly suggest you start reading some dashcam forums. You'll see stories from people who have indisputable surveillance footage of crime, and are told

I really highly suggest you start reading some dashcam forums. You'll see stories from people who have indisputable surveillance footage of crime, and are told that it's not worth the time it would take to investigate/arrest/prosecute, or that even a clear video of a vehicle and license plate is insufficient evidence if it doesn't also clearly capture an image of the driver (in most jurisdictions, the driver is guilty of infractions, not the vehicle's owner). Similarly, you can find plenty of stories of thefts which were deemed too low-value (in absolute dollar amount) to be worth police effort despite on-property surveillance clearly showing perpetrators. And the same for other types of crime. 24/7/365 audio and video of every person in the city would not change this. If someone told you it would, that person was lying to you or was misinformed.