Great as an optional offer. It would enable more kids to access drama, sport, music etc, if it is not possible or the inclination of parents to take them . Great option for working parents and good for all kids to have a range of interesting things to do.
But compulsory ? No way. One of my DC has specialist music tuition that is way beyind general school music clubs, I was involved in sport at a county and national level. We needed the specialist coaches to train for competition , not our PE teacher or a school club.
Some of the academies in our area operate a compulsory school day til 5pm , and it works well. It is an area of multiple deprivation and there was a big problem with anti social behaviour 3.30-5 when the kids were unsupervised.
So I can CHOOSE whether to send DC to a school that does 8.30-5, or to one which finishes earlier. Choice: great, by law?
Get your Govish claws off my DC, off my role as a parent and out of my family !