Private schooling offers more than just good grades or access to some mythical old boys network.
Regardless of whether it’s true, people think it means that their kids will stay out of trouble, some see it as a status thing and others believe that it’ll give them confidence in themselves and a work ethic to succeed. It also offers opportunities (sports, trips, etc) that kids might not get otherwise.
Maybe a discussion for a different thread though given that I still think he’s a muppet paying for it when IMO he can’t really afford it.