It was a rhetorical question, perhaps improperly phrased as such. The point being that they have barely even begun to attempt to scratch the surface. How effect

It was a rhetorical question, perhaps improperly phrased as such. The point being that they have barely even begun to attempt to scratch the surface. How effective are rovers at doing this? Shouldn't the ultimate goal to be to gather data to allow more extensive exploration (likely by humans)?