IMO you highly underestimate the amount of processing and storage video surveillance requires. There is just no good way to determine if you took that pen or made the newly illegal handgesture towards the wrong person 12 years ago unless you have enough storage to keep all the footage around and the processing power to search through it or prepare it for new types of queries in reasonable time.

Also, have you considered AI being necessary to fill in for missing surveillance footage if the cameras are failing (the ruling class)? E.g. the whole Epstein (PR) disaster could have been avoided if the cameras could have been kept running and the footage post-processed in time.