Yes you're right, the British and French beat back the German offenses after adapting to the new tactics and intial shock. I supose that's a even bigger sign that the German forces had simply ran out of manpower and resources - had they adopted these tactics and strategies even a year earlier, things might have changed significantly.

They could have forced a favorable armistice in the west - and they were trying to. The offensive was done in hopes that they could either force France to capitulate (with the reasoning that it would cause mutiny among the French soldiers, which had increasingly occured after the Nivelle Offensive) or to buy time while the Germans built permanent defensive fortifications along the line to hold the Allies back.

In the end though, it is amazing with what carnage Trench Warfare in World War I did. In 1916, before the Battle of the Somme, the British were engaged in no major battles and still suffered over 100,000+ casualties.