All secondary new schools (Academies) I’ve ever worked in have new, well-maintained 3G pitches, which are hired out to the public as much as possible most evenings and weekends for much needed extra income - is this ‘charity’ school you refer to a private operation?
I would counter your argument of taking facilities away from schools by stating we should adopt the US approach in this scenario - make schools the safety net for all kids when it comes to investment in young people’s sporting development and potential. So many kids I have worked with who have that potential are let down by uninterested parents or, worse still, parents who can’t afford the modest subs that local clubs charge them (coupled with the add ons of kit, new boots etc).