This is one of the issues with the modern cancer cures, thst they are very specific to the cancer, the patient, need one off lab work for each patient and this makes them very expensive and not affordable to many. Despite having public healthcare the managers of it still need to decide what to spend their limited funds on.
You're right about the specificity - Hep C is a bigger-population target than a lot of cancers are - but a lot of the new approaches are looking to be inherently more "personalized" to compensate.
I think it matters because oftentimes insurance companies won't cover treatments if a cheaper form of treatment exists. It doesn't matter if the old treatment is less effective or a much worse outcome for a patient. This is especially true for "new" treatments.