Simple for us. We live in one of those inner city educational black holes that existed two decades ago. And not only was state provision struggling, but there was a desperate shortage of places, so much so that DS was not allocated any secondary school till summer half term and then in a school on the other side of London.
Local choices were: move, rent in another catchment in advance of 11+ (very common), tutor for a distant grammar/selective, play the religious card, or pay. Paying seemed the most straightforward though it meant me effectively having two jobs whilst raising children and looking after elderly parents. I really don't know anyone who sent their kids to the catchment secondary, which was 93% FSM for a decade or more - the highest in the country. (And which has an inspirational head and which did a good job in providing a safe and secure learning environment for the kids who really needed one, but without perhaps the resources to provide stretch/aspiration for its most able.)
London indies are then a whole different ball game, and it was then a question of fit, and who would take them. We wanted co-ed for DD (I went to an all girls school and wished I could have gone somewhere that took maths/STEM more seriously) so she ended up commuting a fair distance at 11-16. DS was lucky and gained a place at our nearest selective secondary.
Had we lived elsewhere they would have gone to state schools. What is particularly weird is that some of the parents we know, who are most vehemently anti-private, and who have passed on these attitudes to their DC, both could have easily afforded private but took the renting in catchment option. I may be biased but am reluctant to allow them any moral high ground.
Its fine. DC not only had a great education but enjoyed it and have remained intellectually curious. One did not get into Cambridge, despite having a huge super-curricular interest in his subject, whilst the other, with our support, did not apply.
That curiosity and education will stay with them. Oxbridge might have been nice but is not necessary. There are plenty of other strong departments in the UK which will nurture interest, provide any technical skills required, and open the doors they want opened. With the obvious advantage of being a bigger fish in the pond and without the stress of the short terms and a cohort including a fair proportion of over-achievers.
One slight oddity of the debate about Oxbridge recruitment is its one-sidedness. American Universities recruit on a more holistic level, as in what will this applicant contribute to the University and campus life. Oxbridge, perhaps rightly, does not. Amongst DCs classmates were a future president of the Oxford Union, several rowing blues, a leading member of Footlights, several choristers and a surprising number who have stayed on to take PhDs, with some interesting scholarships and prizes along the way. Not exclusive to private schools, but good schools can do a lot to nurture broader interests, which in turn allows students to contribute constructively to wider campus life.
I can think of one boy in particular who was an absolute standout at school and continued to be the same in several spheres after being fished from the pool for Oxbridge. With the increased competition he probably would not have got through this year. His loss yes, but also a loss for the University.
As Oxbridge becomes more problematic, I think we are already seeing some pupils whose accomplishments fit with US recruitment patterns head across the pond. London is a good fall back for many, but not, perhaps for those very suited to the broader aspect of campus/college life. Indeed for some, the US colleges offer the advantage of continuing to spend real time on sport or music whilst gaining a top class education.