OP, I think yours over-simplifying the private v state debate tbh. Anecdotal evidence is pointless really - we can all think of someone who went to private school and ended up on benefits or whatever. Similarly, the “Well I went to state school and got better GCSEs than my cousin who went to private” etc etc is all meaningless.
I feel like I’m stating the obvious here, but so much depends on your family background / support; attitude to education; confidence levels; area of the school; mental health - a whole host of factors really that contribute to us becoming who we are.
Some private schools are crap tbh, but I think the best thing about the ability to pay for private education is that it affords you a level of choice. If you don’t like the school, you take them out and find a new one.
There’s a hige difference between the London selectives schools where anything vaguely resembling a mediocre performance is regarded as failure, compared to some sleepy, country prep. When you say “private school” what do you mean? They vary enormously.
In London, simply being able to pay for an independent education does not mean you have choice or will actually get a place anywhere. The odds of a place are often 1 in 10. Super bright DC are rejected all the time. Even the so-called “back up schools” or “softer” options still have 4 or 5 applicants for every place. You can throw as much money as you like at any one of these schools, but if your child doesn’t get through the assessment processes, they won’t get in. This is why so many end up boarding, or families are pushed into the Home Counties to seek less competitive options.
If I lived in an area where the only differentiator was the ability to pay and you could pretty much waltz in to your local independent schools, I probably wouldn’t bother tbh. However, if it’s a difference between the local “outstanding” London comp which gets 20% A-A, or a host of local independents which achieve around 95% A-A, then you can see why parents and DC jump through all the hoops if they can afford it and are told their DC have a cat in hell’s chance of a place at one of these independent schools because the difference in standards and expectations really is startling.