Having been recently diagnosed with Crohn's I 100% agree. Getting skinnier during a bad flare makes people think I'm in better health, because I look a certain way that aligns with their expectations, but it really just means my gut isn't absorbing any nutrients. Turns out being at my lowest weight in years was a Very Bad Thing and not a sign I was doing anything right.
Which, again, is an interesting juxtaposition with my partner who weighs more than me but whose body functions correctly and whose biomarkers come back normal, unlike mine.
All of these diseases have significant input from bad diet and metabolic disorder. Alzheimer's is considered a variation of t2d in some circles.
EDIT: Also, to my previous anecdote, despite being the skinny one compared to my partner, I actually do have several heart problems! (Thank you inflammatory diseases.) But you wouldn't guess that by looking at me, because weight is not a 1:1 indicator of health.
A lot of diabetics taking it to regulate blood sugar (particular the feedback loop with insulin and hunger) have said it's changed their life... but for people who are merely overweight I think the benefits may not always be worth the side effects. IMO the correlation between weight and health is not as strong as people often assume.
Anecdotal, but if you looked at me and my partner, you'd probably assume I was the "healthier" one based on our respective body types. But they're strong, fit, and rarely get sick (knock on wood); meanwhile I'm a lifelong wimp with a host of autoimmune issues. I outsource all of the heavy lifting to them, literally—if the trash is too heavy for me to take to the dumpster, they get to do it instead :P
So to your point about health crises, yeah. It seems foolish to put my partner on a weight loss drug just so they could "look" healthier while nursing a bunch of unpleasant side effects that would make them far sicker than they were before.