Of all of the people I know who struggle with either gaining or losing weight I only know 2 people who found changing their diet actually affected their weight

As much as I agree with the rest of what you said, I’m literally an example of how diet can affect your weight. I had a terrible childhood growing up and was >250# all through high school because I ate shit food and drank a ton of soda. When I went to college I couldn’t afford that shit and actually had to change my diet and I dropped 70-80# within a year, and my now mother in law discreetly asked my wife if I was OK because here parents were seriously concerned for my health.

There is definitely a middle ground here where there are a lot of extenuating circumstances that lead to obesity, but there’s also a ton of terrible food packed with empty calories that are specifically formulated to keep you addicted to the dopamine hits, and its superficially cheaper to eat shit food than to buy whole foods and make real food. Especially if you have no equipment/spices or no knowledge of what to do.