Yeah, complaining about overtreating cancer is taking the libertarian angle too far...which wouldn’t be the first time libertarians took things too far.
I had some "routine" blood tests on record from several months prior to taking a new medication with great potential for side effects. These tests proved that an anomaly seen after taking the new medication was probably not caused by the medication. Otherwise, my treatment might have been needlessly modified, thereby reducing the effectiveness of the new medication.
Humans are extremely complicated machines and it is almost impossible to have too much data.