Can you provide evidence that a statistically significant portion of the population have managed to maintain weight loss in the manner you describe?

The evidence I see does not support your claim. Obesity rates have only gone up during my lifetime and the folks I know in the medical field have consistently mentioned how diet and exercise simply does not have any sort of patient compliance. The folks who successfully do it are outliers.

I will go for the harm reduction principle on this one. The molecules themselves are trivially mass produced for less than $10 a dose and are already being sourced for that cost by folks who are willing to take a bit more risk to do so. Cost seems to be about the only major side effect so far.