While your description of the participants is fairly representative, I don't agree that it is theater. As long as our justice system is adversarial, its protagonists will need to maneuver through it to achieve the desired outcome.

In Texas alone we have 254 counties each of which has at least one felony court (and God knows how many inferior courts). Thus, we have about 450 felony courts. When one considers the range of varying characteristics, training, experiece, and eduction that accrue to all of those prosecutors, defense attorneys, judges, witnesses and defendants, it's a wonder that there is any continuity in our justice system. Of course, due process and trial procedure are subject to variations, interpretations, etc., so the outcomes are likely to vary.