I think you also have to consider the nature and timetables of staff, physical facilities, and what staff are doing with their 'non-lesson' time, when considering why a school might run a club or not.
So if the school has a part-time music teacher, who teaches 3 mornings a week to accommodate all academic music, then there may well not be an after-school orchestra.
If many of the sports staff are also involved in the pastoral / behaviour side of the school - IME many seem to end up in roles like heads of house / year - then the availability of sports clubs may be affected by the number of child protection conferences, inclusion meetings, meetings with parents etc.
If the school has a single hall used for everything from exams and assemblies to parents evenings and careers fairs, then rehearsals by the drama club may be constantly disrupted.
Equally, if the staff are already straining every sinew for every child to get the grades needed, and all the pastoral care required for a challenging intake - food, clothing, places to sleep, removal from domestic violence, investigation of abuse, substance abuse etc etc etc - then it is quite possible that the extra extra overhead of a club may just be the bridge too far for some. Cubs are, after all, an optional extra. Safeguarding is not.