It's not about grammar schools having low FSM because "leafy suburbs." Wherever grammars are based data regularly shows two schools a mile or two apart — one takes ~3% FSM, the other ~25% . Selection using an 11 is the problem, not grammar schools' location.
Nobody tutors for apprenticeships, numpty. And if you close all the grammar schools in the inner cities and leave open those only a few in the leafy suburbs don’t be surprised if not many are on free school meals. Doh!