In addition to military wars, Champagne survived the infamous "Champagne war" in which residents fought bitterly over re-drawing the arbitrary lines specifying the area in which sparkling wines could be marketed as Champagne. Those lying a few yards outside the line could only be marketed as charmat for a fraction of the price.
Recently the line was been expanded so that some of the earlier-designated charmat can now be marketed as Champagne. Because none of the earlier-designated Champagne area was reverted to charmat status, everyone is happy. Of course, consumers now pay much, much more for the wine that was earlier called charmat.
It's all about money rather than quality.