It really depends on what else is going on around the board.
Obviously, taking and holding France means the Allies are advancing in western Europe, and have a new power building units there and unlock the income of the remaining French territories on the board, so in isolation it does represent a major accomplishment by the Allies.
On the other hand, as long as Germany holds Western Germany it hasn’t been seriously impaired, so it’s not by any means a death sentence. It could be that in order to achieve the liberation, the Allies chose to be weaker throughout the entire map, losing strategic territories and handing a win to Japan.