Although weight is undeniably a risk factor for a host of medical comorbidities, especially at its extremes, it's not a guarantee that any of them will occur. And
so the use of a scale to infer the presence or absence of health
ignores the actual person standing on the scale.
Similarly, scales don't measure lifestyle. There are scads of patients with obesity doing all of those good things—exercising regularly, getting enough sleep, not smoking, cooking with whole ingredients, etc.