If you believe this is true, why stop at radiology? Couldn't the same be said for every other non-surgical specialty?

Partially true, and the answer to that is runway -- it will be a very long time before all the other specialties are fully augmented. With respect to "non-surgical" you may be underestimating the number and variety of procedures performed by non-surgeons (e.g. Internal Medicine physicians) -- thyroid biopsy, bronchoscopy, endoscopic retrograde cholangiopancreatography, liquid nitrogen ablation of skin lesion, bone marrow aspiration, etc.

The other answer is that AI will not hold your hand in the ICU, or share with you how their mother felt when on the same chemo regimen that you are prescribing.