The larger the pool of people being drawn from the better tailoring that can be done. If you have 24 kids total in the district, then maybe you put them all in

The larger the pool of people being drawn from the better tailoring that can be done. If you have 24 kids total in the district, then maybe you put them all in one classroom regardless of age and teach that way. If you have 300 kids in the school district now you can do separate classes for each age. If you have 900 kids, now each grade can have 3 classes and maybe one of them in each grade can be set aside for advanced students and one for slower students. If you have 25,000 kids in the district, now you can start doing things like an entire G&T school, and/or a school for the students interested in performing arts, and/or a specialized vocational high school. Unfortunately, the trend in the US is towards micro-catchment areas mostly as a legacy of racial segregation efforts and because of the continuing desire to have socio-economic segregation.