So from the outset we can see from your chosen example than there is no necessary conflict between ownership and quality of education.
well not if you are in that great school but there will be if you are in competition with them which will inevitably occur between private companies paid per pupils
Education should not be a scarce resource hoarded by those lucky enough to possess it. Education is meant to be shared. Its power does not decrease with the giving. It is an economic and social good,” said Sir Michael.
That is the head of Ofsted today telling off the private schools for not doing much to help the state sector BTW. Despite all their wealth, their charitable status, their high quality teaching, their massive sports fields and facilities apparently they dont help much …who would have thought it but they are a bit selfish and less egalitarian and inclusive.
If we use say supermarkets as an example and assume only tesco and asda are the only two. If asda was rubbish it would not matter as we would all go to Tesco. This is not an option with education as some will be stuck in asda. The goal is to make sure that tesco and asda are identical. That is we want to give everyone an equally good start in life. I dont see how the private sector with schools in competition helps us achieve this tbh. I am sure on an individual basis , like a faith school or academy [shudders] , they can perform well. Its not a solution for improving education for all but it may be one for improving it for the few.