People tend to behave if they know they are being watched. Yeah it's not going to stop crime 100%, but I bet you it will (and it has) help reduce crime by double digit percentages.
Look at places where there are CCTV cameras all over, there is very little crime there compared to the United States. I won't use China as an example because then you are going to attack me for saying it's an authoritarian state. In that case I will use democratic examples: Taiwan, South Korea, Singapore.
> People tend to behave if they know they are being watched
At long last, we have created the Torment Nexus from classic sci-fi novel Don't Create The Torment Nexus...
> People tend to behave if they know they are being watched
People tend to behave in the ways that the people who own the surveillance apparatus want them to behave. This assumes that the people who own and operate the apparatus (oftentimes private corporations) can be trusted to monitor and act in the best interests of society. Unfortunately, the people who own and operate these have shown that they are largely untrustworthy and motivated by profit and power.
Regardless, most people would not sacrifice personal agency and democracy for supposed safety. "Behave" just means "obey" or "comply" when used in the context of "people tend to behave if they are being watched"; consent is notably absent.