Indeed... cameras need to be maintained when they are broken, the video quality of cameras is not really good for space reason so the footage is not usable all

Indeed... cameras need to be maintained when they are broken, the video quality of cameras is not really good for space reason so the footage is not usable all the time, the videos need to be stored somewhere with a good backup system and must obey local laws about data retention, different cameras are managed by different people so you need some paperwork to access everything which might be needed, they need to be checked regularly to see if they still work fine... Putting all of this in place is not really cheap and easy to maintain all the time, that's why not everything works 100% of the time.