At the risk of sounding high-handed, I didn't find the programme that shocking. The bits about Chris's brain "wiring", yes. But the actual classification of food, and the makeup of a typical UK diet, no.
We're sitting here arguing the toss about Lloyd Grossman v homemade bolognese, but that family in Stockport was wall to wall nuggets, readymade kebab meat (?) - things that are very far into the realm of ultraprocessed. If that lad lived on a diet of Lloyd Grossman sauces, white pasta and cheese no one would bat an eye and I doubt he'd have the cravings he did.
There are lots of people living in food deserts, pushed for time, in poverty, relying on metered gas and electric that makes a 20 minute nuggets and chips meal more viable than a slow-cooked dhal or whatever. That's before you get to teaching people from quite a young age about the basics of making a meal. Not - here's a bolognese, but here's a fried egg, here's how you cook pasta, or rice, or what you do with a broccoli. Here's what seasonal food means. So Nestle et al come along with products that entice people and seem to solve all their problems in one - hard to resist really. And by the time their kids are two/three, their habits are quite firmly ingrained.
FWIW, I run a food bank - people come along each week and choose for themselves from a selection of tins, ambient items such as bread, fruit, veg, some meat, some dairy items. Various ages, quite diverse demographics. I'd never thought about our typical selection through the lens of UPF but did after this programme. The most popular foods/ingredients week on week are chopped tomatoes, tinned fish, milk, cheddar cheese, biscuits, cereal (all sorts... I'd say muesli/granola the most popular), apples, bananas, tomatoes, other fruit and veg when we have it in (with the exception of things like turnip and celeriac which very few people want), bread. If there's a range of bread on offer I've noticed that the UPF bread (soft white burger buns from a supermarket, rolls etc) will go first, ahead of (literally) handmade sourdough surplus from a bakery collected fresh that morning that sells for £4.50, but other than that I'd say that actually - cost considerations aside - the people we serve will choose less processed items. It's anecdotal, obviously, but leads me to think that the most critical factor is cost.