I read a fanfic once that posited in fantasy worlds of common healing miracles, conditions like diabetes would struggle to be recognized. If everything else can be cured with a simple wave of a wand, who's gonna waste time studying mundane methods to solve something that's either constantly patched up magically, or "clearly beyond magical repair?"

It's possible to include the mundane into the fantastic. But you have to actually let the fantastic BE FANTASTIC, and not just ignored when convenient.