Ultimately the problem is that many people are happy to believe what they want to believe, and no amount of video or audio evidence will change their mind about it. There are sometimes people who just need to be convinced, but the way things run these days, those people usually aren't the ones in power.

Pervasive video recording means we get to see more of the day-to-day atrocities being committed but that doesn't matter much in most cases because the people in power already knew and don't care.