Here's a 1992 letter-to-the-editor in the NYT by a citizen named Robert E. Lupinskie suggesting videotaping trials without juries, then showing the juries the edited videotapes without all the disallowed testimony, sidebars, adjournments, and other time-wasting. Serving on a jury takes up a lot of days because the judge and lawyers work on other cases in the morning and afternoon when the trial is not in session. For example, on the trial I served on, we would normally be told to show up at 10 in the morning, but often the judge was conducted a very serious looking hearing with a defendant in a different case shackled to the defense table, so we'd go sit in the jury room until 10:30 or 11:00. We'd take 90 minutes for lunch and be out by 4:00. We didn't work very hard, but we were there a long time. Testimony in that trial lasted something like 9 business days, but we could have watched all the proceedings on edited videotaped in 3 or 4 days, working 7.5 hour days.
I can't think of any obvious reason this would be worse than the traditional system and several reasons why it would be better.