The “goal” of these plays (aside from keeping the girls busy), is to help develop latent talents and leadership abilities. If that hasn’t happened with you, 13, it’s a shame, and the production heads really should try to get everyone involved in the creative process.
Not every part of school is optimal for everyone, but by focusing on something other than academics, a much higher percentage of girls are able to feel successful and accomplished.
This is ultimately, IMO, more important than the academics.