Every child should get to go to a good school. *Your* child is in a position of extraordinary vulnerability and dependence on *you*, which comes with an obligation to try to do right by them in particular, just like if you are a nurse you have particular obligations to your patients and if you are an employer you have particular obligations to your employees. That's not an obligation to send them to private school! But it's an obligation to make sure they are safe at school, check regularly what they're learning, make sure they are literate and numerate even if the school fails to make sure of that, and change things if the situation they're in is really bad for them. We wouldn't think much of a nurse who doesn't give their patient the recommended treatment because 'why are you any more deserving than destitute people who can't get treatment'. The nurse may go join Doctors Without Borders if he wishes; that would be a commendable thing to do. But when people depend on us, and have no resort to anyone else, we must do right by them.