In addition to potential technological difficulties, the Judge cannot monitor the proceeding for foul play (ie third parties coaching invisibly from the sidelines).
People have waited a long time for their day in court and deserve some in-person satisfaction. They deserve to see the judge in person and talk about their story. Not through a video screen. That is not fair.
Skype and zoom have been around for years and yet people still fly across the country and across the world to have in-person meetings when there are important matters at hand. In-person counts.