My town has two super selective grammar schools, the remaining schools have averages between 30-low 50s% excepting two schools with averages in the 70s (one UTC with very narrow curriculum). It's a conundrum because on the face of it the town should have good schools, young/affluent/professional population - but it doesn't.
I don't think the problem is the grammars - they have very small local intakes - but that years of terrible schools with horrendous reputations has led to 'middle class flight' to the many local private schools, the three adjacent counties or moving house to the intake area of the 'good school' (which costs as much as private school but I guess you only have to do it once so it works out cheaper if you have more than one child). We can't afford private school or moving so went went out of county. I'm part of the problem but there is no way on earth I would send my children to any of my local schools.
The county we've 'chosen' is truly comprehensive, pretty affluent I guess, rural, completely lacking in any diversity. The bad schools, the ones people shudder about, have averages in the high 50s/60s. Everything else is 70s & the two schools you really want to get you kid into are around high 70-mid 80s (depending on year) with good progress 8 scores (though nothing like our grammars that have scores of above 0.6
)
The other two local counties have very similar results. We live in an area where anyone who can opt for anything but local schools does so - therefore the local schools are never going to improve. If you can't escape I guess you become super involved parent, cross your fingers & hope they get good enough results to go to the grammar for 6th form.
It isn't just bad results - they lack everything that a sharp elbowed parent would look for - no MFLs, limited sciences, crappy 6th form options, no music, very limited sport & extra curriculas, timetables padded out with non subjects or narrowed down to the absolute minimum. Lots of intervention classes but nothing at the top end. They are either snazzy new builds that scream 'we were a failing school' or depressing smelly dumps that scream 'not quite failing but no-one really gives a fuck'. I honestly don't know how they can overcome that. Maybe as house prices become ever more insane people just won't be able to leave!