They are supposed to, but often times they don't and there are no consequences for it.

Current diagnostic setup relies on humans having vast expert knowledge, when in fact it's almost always impossible.

A well trained neural net/LLM will always be better at visual detection because of sheer number of examples it sees during training, compared to a dermatologist which, if lucky will observe no more than 20 patients/day x 270 days a year x 40 years of practice i.e. around 220k samples throughout his lifetime.

MD with other specialties will see significantly less and we are talking about top of the top specialists.

An average MD knows more amount medical diagnostics than than the average Joe, but in principle much less than a well trained AI.

Do we have those kinds of models already? Maybe not yet but, ceteris paribus, we will definitely have them in the future.

IMHO we do have those models already but they aren't available to the public, though their availability would certainly lower cost for healthcare providers.

Yet here we are

Skin cancer is easily treated with excisions if it’s caught early. Better to have ten small false positives than a single miss.

Not sure why this is getting downvoted. In its specific case that's quite obviously not a good example because removing benign spots isn't harmful, but overlooking malignant ones is, so there is no downside.

But if we think a little further and generalize then there is great risk (and by extension, harm) to delegate diagnosis and treatment (of health issues in general, including potentially or supposedly fatal ones) to ChatGPT and similar tech. That we'd end up with a net positive is far from obvious.