There are 40,000-hours of videos of the Jan 6 riots. To put that in perspective, there are 2,087 work hours a year, at 52.33 40-hour weeks. It would take almost 20 years working full-time, doing nothing else, to view all of the video. Add making evidence notes and copying salient footage, and the decades it would take to use this video as the basis for all trials would result in denying all of the accused anything resembling a speedy trial, as guaranteed by the law.
In bank robberies where a robber kills someone on video, the video showing them standing around waiting for money to be bagged, if it exists, is not shown. The video showing evidence of the crime is shown. The prosecutors who showed video evidence of crimes in Jan. 6 cases are not compelled to show videos of nothing happening. The court would rule that as being inadmissible because it isn't relevant.