It can be - when it’s involving the parents, listening to the community, and is not driven by profit. But it also shrinks the spaces available so that there are winners and losers in the lottery, and pulls away funding from the public school system. And as it’s often administered by a private corporation (either for or non profit), there is often little transparency.
Don’t get me wrong, I’m not anti-private schools, as I send my own kids to one. I just want to point out that there are plenty of successful public schools (read up on the Decatur City schools in Atlanta, for example) and unsuccessful charter schools. If we want to have students that do well, we need to figure out what works to best educate all children, and implement that across the country. that means taking some ideas from the private sector and applying them to the public, and it means the opposite too.
Me? Montessori, FTW! Gives you good teach student ratio, without having to make classes tiny. It allows kids who are good a self-management to do their thing, and those who need more guidance also have it. It works well with the theories of childhood development of people like Piaget, and it’s is flexible enough to incorporate need concepts and ideas, without losing the core of the method.