Funding for public schools is based on local taxes with help from the State and Fed govt sometimes. It's a really unfair system. I taught for 38 years and watched the modest community struggle to provide really good schools for their kids. Your bright, extroverted kids will be fine in a class of 32 unless they get bored. But not all kids learn the same way. Quiet kids get lost and confused kids become disruptive.
I think the best you can do is develop a real partnership with your child's teacher. Read all summer. Read anything. It really helps. Write a journal TOGETHER. Draw & collage.Use the computer creatively, not just to play games. Oh you know...