This news from the UK is concerning and the UK is slowly turning into a dystopia but still your reasoning is flawed.

The cameras are there to discourage crime and for use in court as evidence. Solving a crime still requires time and energy. Policing is a resources game.

So of course petty crimes are still going to be committed because it’s resource intensive to have someone monitor all the cameras. That is until it isn’t and you have a backlog of video footage of crimes and AI powerful enough to detect crimes being committed in real time. Even then though police work is still required if AI isn't using face or gait detection and/or these systems aren’t hooked up to a database that has linked identifiers to real people. But even those can be defeated with a bally and a limp.