but how are the children punished?
the state will still pay for the third, fourth, fifth, child etc to have a free education and to receive any necessary medical treatment on the NHS. They aren't being penalised compared to their older siblings.
the money doesn't go directly to the children, so any benefits for the first 2 children will go into the general family budget. It's unlikely that a parent would buy their oldest 2 kids christmas presents, for example but tell the third 'Sorry, Keir Starmer says santa can't afford presents for you.'
I understand that perhaps a family overall would have less money to spend than if all the children in the family were receiving child benefit, but
a - not to get into stereotyping but that's assuming the extra money is spent on the children, which it is hard/impossible to put restrictions on unless you start thinking about introducing food stamps rather than money
and b - that would also be the case for multiple other factors - e.g. overall a family of 2 would get more money if their sibling was disabled - does that mean that children without disabled siblings are punished by the state? A family with children of different sexes will be a higher priority for a larger house once they get over a certain age - does that mean a family with 2 boys is being punished by the state?
A family where the parents both work as admin assistants for their local hospital are going to have less money coming in than one where the parents are doctors - are those kids being punished? The family's income is still coming from the state, and the state has chosen to pay doctors more than admin assistants...
I think 'a family has less money to spend because of choices they made therefore the state is punishing their children' is a false equivalence.