I certainly think that there's a discussion to be had about this. Personally, I don't object to some people spending the vouchers on treats or luxuries per se (from the common 'you're frittering away taxpayers' money' pov - I'm not the treat police) but my concern is IF children are going without the food they need, even when the parents have been specifically provided with the means to buy it, which does seem to happen in some cases.
I'm sure the majority of parents who receive these vouchers will appreciate and use the value of them in their overall provision for the children, regardless of which particular goods and in which particular shops they exchange them for. We don't hypothecate child benefit specifically for our DS's personal requirements, but it's a very valued part of our total family income, from which we provide him with everything that he needs (and some things that he wants, as well).
I've seen it reported (from official/reputable sources) that there's evidence-backed concern that a significant minority of less privileged families don't just rely on financial help towards providing meals for their children, but that, unless cooked/prepared food is actually handed over to them (whether at school during normal times or delivered to them during CV lockdown), their children will go hungry.
I also see frequent reports of children relying on FSM (in normal times) for their only hot meal of the day. Is this accurate? Do plenty of households really not have access to an oven/hob/microwave (or the funds to run them - surely not a lot for the latter two?) and do the adults of the family only ever have cold food? I'm genuinely interested to know. It sounds like a lot of very valued help is getting through to those who need it, but also that a proportion of parents are neglectful, even when money is not an issue. Of course, this is also the case with some well-off parents as well.
I also don't understand what I've read recently about some children still being allowed to go to school during these current circumstances, even though they have one or both parents at home and not working, because it's officially adjudged that they will be 'safer at school than at home'. Not just non-NT kids who won't cope without the routine but actually specified as 'safer', with the clear implication that their parent(s) pose a danger to them. How can this be? I really don't get it. If a child's home environment is not safe for them during normal school hours, how can they be safe outside of school hours and at the weekends and in school holidays? 