There are a few issues that hamper some state schools nowadays from providing an all around education.
Firstly, it depends on the facilities that schools has available. There is no standard that schools are built to so whilst one might have a swimming pool, another has no field.
Then their is parental preference. The parents that are invested in their child will seek out the 'best' schools. They are more likely to engage with the school and support PTA's or make voluntary school donations. Therefore no matter how much money you chuck at a school the gap between the best and worse schools in a borough keep growing.
Also student satisfaction is not one of the required measurements that state schools are judged by. The subjects that create well rounded individuals such as performance/creative arts are not valued as highly as the traditional subjects. Quite often the way GCSE options are timetabled it makes it impossible to for children to take what really interest them (or it is not offered at their school) and unless the parents can fund activities out of school hours, many children drop these subjects from Year 9. There is little surprise that by the time a child finishes year 11 that they are buckling under the academic pressure and are suffering from burnout. You can see this in the increasing levels of mental health being reported in young adults.
Finally, there is the increase in low level disruption and lack of personal responsibility. If you have a class that can not behave appropriately it takes twice as long to teach them anything and the 'fun' aspects are stripped out in order to focus on the basics.
The solution is far more tricky because it will require a combination of the radical review of secondary schooling, decent funding for SEN/CAMHS/child social services and some parents/children changing their mindsets and take greater responsibility for their actions (including the consequences).