It's not. Private schools I've heard of and experienced have strong academic selection criteria on top of being incredibly expensive. My son had funding for a

It's not. Private schools I've heard of and experienced have strong academic selection criteria on top of being incredibly expensive. My son had funding for a time for nursery and was moved into the prep school. It was like seeing a foreign school. Class sizes were naturally smaller and I noted things such as their morning 'prayer', which went along the lines of "I vow to work hard today in everything I do", where as my morning prayer in an RC school was the Our Father. I also saw kids in my sons class who, at 3 years old, were able to compute divisions in their head and articulate in a way that I've never seen a child that age speak. These places are optimised for kids who have a lot of money backing them up and the brain power to boot. In some respects, their parents ability to simply hire help to ensure their kids do well academically must be noted too.