It does work for a small minority of society. For the rest it does not.
Also, it's very hard to make something work which huge monied interests design products in a manner to ensure you fail. Are you just going to ask your grocery store to stop putting salt-fat-sugar in bright packages right by the checkout, packages and foods that are being developed by well paid groups to get you to consume as much as possible.
It's also very hard when your body is designed to do one thing. Consume as many calories as possible so you don't starve to death, because your genes are screaming at you "Starvation is coming, it always does".
So the only 'cool' statement is yours by completely not understanding the situation at all.
Junk food is convenient and more enjoyable, at least in the moment of eating. In the last 60 years there have been changes to the environment that reduce physical activity (more automobiles, less walking, less strenuous physical labor on the job) but I think that the most relevant change is the abundance of highly palatable calories. 60 years ago we largely didn't have "convenience foods" and the fastest snack you could make yourself (like a cold sandwich or a piece of fruit) didn't have the "craveability" of Doritos or microwaveable egg rolls. Back then the average American could afford to buy far more calories than needed, but those calories would take prep labor and/or not be highly palatable, so in practice many fewer Americans overate buttered popcorn the way that people overeat Doritos today.
America was on-average wealthier than most of the world and an early adopter of highly palatable convenience foods, so its obesity problem came on earlier. Global obesity rates are rising as more people globally can afford microwave ovens, frozen pizzas, drive-through restaurants serving french fries, and other such aids for high speed ingestion of delicious, calorie-dense foods.
Most people who need to lose weight cannot willfully maintain diet alterations in the long term. They go back to old habits. For 99.9% of human existence starvation was a much more common health threat than obesity and we're just not "wired" to experience excess food intake as a threat. The GLP-1 drugs like semaglutide reduce the desire to overeat, regardless of how palatable the food is, so people who could not lose weight before are able to eat less without having to consciously suppress desire every day.
Advice doesn't work that well in general, especially when it's vague and general advice like that. I would also guess that there are competing forces trying to make you eat their product and that they put a lot of money into that.
Because humans (like most animals) are optimized at a deep level to seek high-energy foods, and neither encouragement or shame are powerful enough to override that.
This has been done for a while and mostly doesn't work.