I would disagree, and here's why:

The bulk of our calories should be coming from carbs, and healthy carb staples are very cheap and readily available anywhere: rice, flour, pasta, etc.

Food deserts, while I don't deny exist, aren't a problem for the majority of the population. Most people living near any city over 100,000 likely have access to multiple grocery stores.

The cost argument falls flat when you consider that junk food, alcoholic beverages, meat and dairy, and high calorie nonalcoholic beverages cost a lot more than real food staples.

Availability and cost really only impact fruit and vegetable consumption, but historically, most Americans have never consumed enough regardless (unless they were vegetation/vegan). It's a cultural thing, I'm sure.

A breakdown of food spending also indicates that a large proportion of food spending tends to be "eating out", which is not cost effective and gives a good indication that people are often misspending their food budget.

The issue of time is also not a good reason when throwing ingredients in a basic pressure cooker, rice cooker, or , slow cooker takes minutes and you can batch cook an entire week's worth of food with minimal cost and effort. As with the point above, it takes more time to eat out, and learning to prepare basic meals is a skill that every adult should have.

Eating cheap and healthy isn't impossible, but someone needs to be willing to at least break their poor eating habits first.