Proving a negative is a hard and sometimes an annoying in itself ask plus you're probably frustrated with the general attitude to this kind of conversation (especially if your main expectation/experience is others don't like the pill answer out of spitefulness) but that doesn't make this kind of response any more okay here.

For others open to listening to why it's often out of reach: Outside the go-to "motivation" type discussion gravitation (and, keep in mind, not everyone can just 'motivate themselves past their addictions' in the first place or they wouldn't be addictions) it is also disproportionately hard for those struggling in other ways of life (financially, mentally, physically/genetically). Some of these can be cascaded effects, like support systems (e.g.not everyone's partner is willing or able to go all in on it like above). Others can be that it is medically not as easy for some people to lose weight at a given intake amount which makes it just that much harder.

Most people would like very VERY much to be fit. That most still aren't fit should be a good indicator it's out of most's reach to "just eat less" independently. All this said as a person who is not overweight themselves but has been around many people in different situations, abilities, and luck that have left them unable to be so as well.