But Bonsoir, while breadth is no doubt more common in private education, there is nothing that says that a child from a state school cannot have it, through a mixture of school provision and outside activities.
Dd is not the only child who gets a broad education from a combination of school and outside activities. She has several friends who have already acted in professional performances, who take singing lessons with specialists, play several instruments and are highly proficient in sports- and they have only just chosen their GCSE options. All the state schools dcs have attended have had very good music provision, several local comps offer a range of languages, there is a Latin club at dd's comp, there are science clubs, there are excellent (and not too expensive) drama and ballet schools locally, some of her friends have quite advanced sports coaching (as in preparing for possible future Olympics). I engaged a relative to give dd German lessons. Several of them can sail a boat. Many swim very well- you can learn that in a public pool or even in the sea (which is what I did) as well as in a school pool. Cookery lessons can also be supplemented at home- I could cook a 3 course dinner by the time I was 9, simply because my mum encouraged it.
I used to think we were freaks to provide so much for dcs- now I realise that we are not at all unusual for this LMC area.
Not having everything on school premises doesn't mean you can't have it at all.
Obviously, this is not going to be the case for all state educated children. But I am a bit fed up with hearing that only privately educated children can possibly know anything beyond their narrow range of school subjects. Tell that to dd's friends who spend their breaktimes discussing Stanislavsky's method.