It's interesting that overall spending doesn't decrease that much in the end, although shifting from snacks to fruit is the kind of change health advocates have always wanted?
This is a commonly repeated claim but it's usually not true. Fruit is, in fact, pretty cheap:
In the US, bananas average $1.68/kilo: https://www.numbeo.com/cost-of-living/country_price_rankings...
A kilo is usually ~6 bananas. So a banana costs maybe 28c on average. Find a cost-competitive ultra-processed snack for the calories and satiety that a banana provides. Healthy eating might not is cheap but junk food, specifically, is not usually a cost optimisation.
Having enough fruit for a family for a week, indeed as a sibling posted, accounting for spoilage or just bad items in the delivery, takes a substantial amount. In volume and in cost.
On the other hand, crappy snacks are typically <€1 or <€2 per kg.
We make the choice to buy fruit. But also we are well off enough to be able to do so consistently. There are also other costs of having to spend more time getting the fruit, preparing it for the kids to take to school. Not everyone has the time or sees the opportunity to do so. I’m very reluctant to just blame those people and say it is their choice to eat crappy food.