For balance, I'll say that I'm planning to send my 7 yr old daughter to a private secondary school when she's old enough.
She's a May birth [slightly premature, was meant to be June/July], is maybe slightly above average academically, but is quiet/shy, well behaved, so easily overlooked in a class of 30. Also quite easily led.
I want the best for her. I know that my money can get her grades that will make her, on paper, the equal of significantly brighter but less wealthy kids, and probably also help buy her softer skills, behaviours, values, maybe even a few contacts, that'll mark hopefully her out in the world of work and so on as someone who's, you know, 'officer material'. I doubt she'll be bright enough for the fees to get her into even the tier of universities just Oxbridge, but say bottom end Russell Group feels about realistic.
I know, of course, that there are less well off kids in her state primary class who would go further if we were to selflessly donate the fees to their families. Of course that's not going to happen, she's our daughter, she comes first.
Let's call a spade a spare here, this is what's happening/how the schooling system works.