That is true, the French (as opposed e.g. the Germans, they blend different varieties much less) in particular do this, and they do it well. So yes, strictly speaking these are blended wines as well. But seldomly any wine maker in France would buy them; it all comes from their own parcels, and these blends are well established flavor profiles. They know their own grapes and what they can do with it.

If you do really high volumes you buy, sure. But again, it's of no surprise if these manufacturers experience a decline of demand.