I think the truth is that we don't really understand obesity and the causes of obesity.
It's really not as simple as "eat less crap" if it were, then there'd be a higher success rate of weightloss maintenance - currently sitting around 2%
There's increasing evidence that obesity has a viral cause in most people and a microbial cause in others- there's very few where it's actually due to eating too much rubbish. And that due to the underlying cause, losing weight doesn't cure obesity, t only managed a symptom of it. Obesity is complex and obesity itself is much deeper than someone being overweight. It's becoming increasingly evident that weight gain is a symptom of the disease and not the disease itself.
Evidence for this theory is based in migratory birds, who when given extremely limited diets, still gained fat prior to the migratory season, despite no increase in calories or loss of activity levels. They also lost the weight following migratory period, with again no change in calorie intake or energy expenditure (because they were captive). The obesity epidemic has spread to "third world countries" PRIOR to the increased availability of UPF and high sugar foods, which again gives evidence to a non-food, viral or microbial cause.
It also explains why some people can eat essentially whatever they like and not gain weight.
So what needs to be done? A massive increase in the research in to the cause of obesity beyond what we think we already know. Which may hopefully lead to LONG TERM solutions. Because people being constantly hungry, and feeling constantly deprived is not a solution.
It would also help if we removed the morality view of obesity - that it's a moral failure which requires willpower to overcome. And an acceptance that like any other disease, some people will require medication like ozempic and that by using these medications people aren't "cheating".