Fair question. i went to a state school, i've come from little (parents emigrated from India and i was born here), no family wealth.
I don't agree with private schools as a concept, especially given the 'charity' status they claim. It's an elites vs the common, the haves vs the haves not. And as we can see, politically, the cycle of private schooling leads to those privleged few going to the same universities and going to the same jobs and leading to the same circles in our parliament. It's not a meritocracy, far from it. you'll do well out of it regardless of whether you excel at school or not.
So to the point, not a fan, don't like them. But, the standard of schooling is incredible, there's no denying that. My kid has 20 kids in his class and 2 teachers. Compare that to 30 kids and 1 teacher in a state school. I was singing "Head, Shoulders, Knees and Toes" to my 1 year old and the 6 year old started singing it in Spanish. i didn't learn Spanish until i was 12.
even if i don't like it, It'll give them the chances i wasn't afforded and maybe open doors that were closed to me. I can't change the system. I don't have massive amounts of wealth, i mean, there's some kids in this class who's parents drive Bentley's and Aston's, so financially we're not even close to competing. But, i can send them to a good school and hopefully means they can build well from that.
This isn't to slander state schools btw, i'm a product of one. But there's not many stand out ones. In fact, the best ones in our area are Church schools, which is funny because it's effectively a closed door to people like me. I know loads of people who get their kid baptised or go to church for a year to get their kid into school and then sack it off.