> We're being told that people are healthy at any size.
Literally nobody in the medical community is saying this. Obesity is unequivocally bad for your longevity.
There is a healthy range, which is a little fuzzy. Some people are healthy at a slightly heavier build, and we know there's some flaws in the way the BMI calculation works for certain groups of individuals. However, there is still always a point where you are medically obese and health problems begin.
It absolutely kills people. Heart disease, stroke, diabetes. There's some studies that suggest it might even be a causal factor for Alzheimers.
> How is it okay to encourage weight loss with an expensive and possibly (likely) harmful drug, but not okay to encourage weight loss with a sensible diet?
First, weight loss through diet and exercise is certainly encouraged. The exercise is intrinsically good for you. Improving your diet is intrinsically good for you. The weight loss adds even more benefits on top of that. If this works for someone, that's literally perfect.
However, diet and exercise clearly do not work for many people. Lifestyle modification is hard, for a whole lot of reasons... some social, some biological. We know this as fact.
If diet and exercise fail, then using drugs to combat the biological (hormonal) drivers of obesity is the current second-line option. And even if there's some side effects, the overall increase in life expectancy makes it worth it.
> Is being overweight a bad or a good thing? Despite all of the research, that part is unclear.
Medically, it's very bad. The research is very clear.
Now, that said, if somebody's overweight they should still feel good about themselves as a person. Shifting the conversation from "you're overweight because you're not good enough, and you should feel bad about yourself" (which is both bad for mental health and counterproductive) to "you're overweight because obesity is a disease, not a personal failing - and the fitness+medical community is here to help you be a better you" is a much better approach.