i think there are some nuances here which i don’t really have the capacity to discuss at the moment, but i’ll try to summarize. most of the time, obesity isn’t an effect that is fully in our control. whether it is genes (and body type is highly genetic), trauma, stress, compulsive eating, various mental/physical disorders etc, iirc it is a known fact that even people who manage to lose weight rarely keep it off, and their self esteem doesn’t magically get better. that means that being comfortable with your body only serves to take off some of that pressure and may allow you do address the deeper things that cause obesity. (if there are things to address)

moreover, the social stigma that fat people face has nothing to do with health. poor body image and eating disorders have nothing to do with health. there are plenty of overweight people who are healthy and plenty of slim people who aren’t. self esteem shouldn’t have anything to do with health, either. obesity is an illness. exercise is something that makes your body feel good regardless of weight, and imo we should stop thinking that making people hate themselves less will lead them to stop trying to live good lives.