It's my perception, Naomi, that in the 60's and 70's I was always reading about clever working class kids who went to Grammar School, maybe free (but very select) University and rose naturally to the top. Politicians, barristers, business leaders, even actors.
The natural order seemed to be people making it on merit.
Today, when I read about these people, they all seem to have attended public schools.
No working class (and few middle-class) can afford to rent/buy a London property and pay all the living expenses for 6/12/24 months while their children take part in an internship.