There are a number of really helpful and dedicated teacher's on here. They work long hours and give up there time to run clubs for their pupils. Parents at the schools concerned treat these clubs like free childcare which in effect they are.
At my dc.s school all after school clubs are run by outside organisations and are chargeable.
Obviously I don't know how much work they bring home but the car park is virtually empty at 4.30 and is also virtually empty in the morning too.
Plus teacher's teach same year groups with same topics on a rolling period so can't imagine much prep work is needed.