Another problem is that the culture does not value those things which empower young people to rise. Even among the top 5% of my high school class, I knew people who turned down full tuition scholarships to the flagship state university because they wanted to follow God and marry a nice boy from their church, or needed to stay home to help care and provide for members of their family. It's traditional and tribal, and looking off toward the horizon and going away for fancy schooling just doesn't rank highly on most peoples' priorities. In a community where many kids' parents attended the same high schools and the grandparents are local, wanting to leave is considered odd.
The only reason I'm not still there today is that for some reason, as a nerd and social outcast, I rejected that path from an early age and my top priority out of high school was to get the hell out. School was hell, but I consider myself fortunate not to be working minimum wage jobs and living in a trailer park like two of my siblings.