For example, my Sony a6000, which can only record 30 minute clips. Also, many cameras have recording time limitations. But this doesn't work with cameras that don't have onboard storage like webcams or PTZ cameras. If all your cameras have their own storage, you can record on each of them, then bring the footage into your editor and sync the clips by audio afterwards. There are a lot of little conveniences you get used to if you do professional live video production with high-end equipment that you often can't replicate in a budget studio.