I was going to reply to the badger point but the thread seems to have taken a turn!
As with the individual approach to making peace with our impact on the planet, we all spend money on different things. If you value good, tasty, home cooked food then you'll be happy spending more on it than someone who is happy buying ready meals and wants to always have the latest iphone. That's not to judge but simply a statement of fact. Raw ingredients are cheap relative to the cost of ready meals. Granted, I have a bunch of steaks in the freezer that are at least £10 each, but they're from a farm on the Black Isle, aged, and 400g each. Quite good value IMO, but if you're trying to feed a family of four on minimum wage then clearly not an option. In contrast I have no family to worry about feeding and so regularly buy £50 bottles of whisky, and my average evening meal will be somewhere in the region of £5-10. I just spent £40 on fish which'll last me a week as my GF's staying so it's for two. There was another £20 in there for the dog. I've also been on ski club trips where we cook food en masse and I've made a tasty curry for ten people for less than a tenner. It just takes a little more time, both for hunting for ingredients and preparation.
I think like early '00's bike prices we all got used to food being cheap. Like dirt cheap. Happy meals for a quid, a can of coke being 50p etc. Explosive inflation (driven majorly by corporate greed) has changed that, but the core is that proper food is still going to be cheaper per nutrient than a ready meal. Maybe not per calorie, but then that's a terrible benchmark unless you're actually starving. The reality is that our parents and grandparents spent a huge amount of their income on food, spent less on frivolous crap, and the food they did buy was much closer to being real. Sure, there was tinned stuff, but the bulk of their diet came from real stuff that was still identifiable as what was either living on the farm, or as it came out the soil. We're so far from that now for many people that people are completely unable to identify basic ingredients let alone actually know what to do with them. But if you take the animal welfare out of it you can buy 1kg of chicken thighs with the bone in from Tesco for less than £3. Cook them without the bones and you can make great stock for other things from the collection of bones that are left, and you get the goodness out of them, and if you throw them in something like cockaleekie soup with the bones still in then you'll get so much goodness out of them the soup'll be solid when it cools. What's the cost of that? Some bread (cheap if you buy, very cheap if you make it yourself), some chicken at £3, and a few leeks. A hearty, healthy meal for 8 servings for less than a fiver. Is that chicken going to be as good or as tasty as stuff that costs 3-4 times as much? Absolutely not. But it'll still be a shit load better than anything you get in a ready meal that's going to be stuffed with fillers. The problem is that families are now time poor as both parents work, probably commute a fair amount, and everyone feels like they're sinking. Plus they probably also aren't confident cooks because we're again so far removed from every family cooking proper food from proper ingredients.
I realise I am saying all this from a position of privilege, we all are to a greater or lesser degree, I can cook well and I can afford decent ingredients that allows me to be lazy and still have tasty food, but the reality is that raw ingredients are cheaper if not easier than processed crap. If you find basic food bland then spices are cheap; garam masala, curry powder, or other mixes like ras al hanout can all add flavour. Or even just the process of maximising flavours by reducing things down; roasting chicken before adding it to soup etc. Yes, expensive, fresh from the farm ingredients are expensive. But cheap cuts of meat, pulses and veg, the combination of which is all pretty healthy, is going to be cheap. Maybe not everyone has five quid to spend a night on food per person, but I don't think it's a particularly unreasonable amount unless there are many people and only one bread winner. A Tesco meal deal sandwich is at least £4 these days and is utterly crap for you. But it's also possible to create healthy, home cooked meals for a few quid a portion. What ready made, process options are ever going to match that?