Maybe each one is run differently but the one at our church makes sure there's enough for a few decent meals. A single person household gets cereal, two tins of soup, beans, two tins of veg, tinned spuds, some pasta, pasta sauce, tea, sugar, bread, UHT milk, juice and some biscuits (depending on what is in stock).
It's not meant to be your sole source of food but an emergency top up for people who are temporarily in a messy situation.
If your Foodbank was only giving you 2 tins of soup and a small bag of oats, a meat pie and some milk, it's likely that is because that is all they have.
Honestly, the volunteers work so, so hard and yet someone is complaining about the inadequacy of what is an emergency service, stocked up by kind donations and largely staffed by people who volunteer their time.
If you now have better fortune OP, perhaps you should consider volunteering and seeing what it's like from 'the other side'?