"The article treats conditions along WWI front lines as static"I don't read that:
"On the opening day of the Somme on July 1, 1916, British guns hurled 250,000 high explosive and shrapnel shells towards German positions"
That's phase one: throw lots of stuff in the hope to destroy their capability to fight. When you think that succeeded, have your infantry walk over and conquer their positions.
"During the beginning of the Battle of Passchendaele in 1917, over 3,000 British guns and howitzers fired a “creeping barrage” on German positions"
Throw lots of stuff to prevent their soldiers from killing your soldiers with their guns while your soldiers advance on their position.
"The Germans developed and perfected the “box barrage"
Throw lots of stuff to prevent your enemy from being reinforced.
"The American St. Mihiel Offensive on September 12, 1918 was preceded in some areas by a seven-hour preparatory bombardment"
Throw lots of stuff for ages to soften their defenses. Stop bombarding when your troops attack. Problem: they dig down deep, wait for the bombardment to end, and then get up and shoot your infantry while it still is exposed between trench lines.
"By the end of the war, most attacks by French, American, and British forces began with a swift but short artillery bombardment that massed thousands of guns on one small area, followed up almost immediately by a ground attack"
Throw lots of stuff to force them to keep their heads down, then immediately have your infantry get up to them (= use artillery bombardments as covering fire)
That's a lot of evolution, partly driven by technological advances. For example, a creeping barrage requires the capability to drop stuff close to your own troops, while not hitting them. That requires good maps and explosives with reliable explosive force (so that one can be confident that shells will carry the desired distance). As another example, concentrated fire requires precision, too.