The problem is not a question of the definition of poverty.. It is a question of how these families found people to recommend them for food boxes and where they come from. Usually those getting foods from Food Banks have to collect them themselves, and if GPs, Social Services etc recommend people for food bank help. it is reasonable to assume they did checks. If not the problem lies with them.
The other thing is that not all boxes of food are free. A well off family may well be having regular deliveries of vegetable boxes and other comestibles from farms and other shops. All of which will be expensive and paid for.
Then you need to remember that when someone well off becomes unemployed, they do not immediately go out and sell everything they possess from house, to car, house contents clothes etc and immediately relocate to a slum dwelling and buy other peoples cast-offs.
They hope and expect to be back in work fairly quickly. Meanwhile they live very carefully, but keep the house, car, clothes, etc I speak from experience, I have been through this, as have other close friends.
Also if someone was in work in 2022, they may well have gone for 2 holidays, but, if they were made umeployed since those holidays, they are probably going on none this year.
I have also found that when people judge from outside without a full understanding of exactly how and why some act of charity is taking place they almost always get it wrong.
DH is not allowed to lift things or walk carrying anything of any weight, for health reasons. I am sure there are people, who look at us, DH, hands empty, with me walking with him carrying bags and is outraged by his selfishness and considers me a put-upon wife. But the real reason is a medical one that is not visible to casual passers by. The same will often apply in other circumstances like this. A family appear to be wealthy, but may be on UB for a short period and may well be getting financial help from family with school fees or expensive car insurance to make sure what they expect to be a short period of unemployment is not too distruptive of the family. Families at every income level help each other, whether they buy school shoes for DGC or pay a term's school fees.