If you think students are not focusing on schoolwork “subjects” and are spending “hundreds of hours” prepping for standardized tests, I think you have a very skewed view of what students actually do in the real world.
Most of my D’s friends have done about what she has - spent about 20 hours reading one book and another 7 or so hours on two practice tests. It has no impact on schoolwork.
Are you tutoring individual students for hundreds of hours?