What I don’t get (and haven’t RTFT so sorry if this has already been covered) is if you’re against private schools on principle but concerned about your own child in a local school with poor Ofsted/results etc. Instead of investing your time and money into a private school, why not invest that into improving the local state school? Join the PTA or become a Governor. Give the thousands of pounds of money you’d spend on private education as a donation for lunchtime or after school music lessons. Fund a class day trip to a museum.
Surely if you’re genuinely interested in equality you wouldn’t mind elevating other children as well as your own.
Also, slightly off tangent I know, but do you really truly believe that Ofsted reports and GCSE results demonstrate how well a school is doing? GCSE results are better because they cream off the best performing students and/or those whose parents will arrange extra tuition if their DC are struggling. Ofsted is very much based on policies, paperwork and a tiny amount of classroom observation. Not necessarily the best indicator for a teacher who goes above and beyond.
For example, when looking at nurseries for DD, we initially visited one that was Ofsted “outstanding”. It had CCTV, reams of policies and protocols, organic cookies etc. The children all looked miserable.
Then we visited one that was “inadequate” because they didn’t have a written policy for child abduction - although the staff could all verbally say what they would do. The children were happy, having loads of fun, lots of outside space for them to explore, lots of cuddles.
We went with our gut, sent DD to the “inadequate” nursery and have never regretted it. The staff are incredibly caring, they might not fill in reams of paperwork but they make an effort to really understand and nurture every child. Something to bear in mind.