Calling small arms and artillery "tried and true" really obscures the fact that heavy, usually water-cooled machine guns (like the Maxim and Vickers models) were really totally new on European battlefields. They had seen service in colonial conflicts, but the First World War was the first time that large, well-funded European armies used them on each other, and the results were devastating.

And, while it's true that field artillery had been around for centuries before 1914, it's vitally important to note that early-20th-century artillery was REALLY different to that used before: the French "75" (Canon de 75 modèle 1897), which entered service at the very end of the 19th century, offered indirect fire of explosive shells, breech loading, and most importantly a pneumatic recoil system. The recoil system meant that the tremendous kick produced by firing 75mm artillery shells was absorbed by the weapon, and the rest of the weapon stayed fixed. Thus, the weapon did not have to be re-sighted after each round, the way older cannons must be. With a weapon like that, armies could and did pump incredible numbers of high-explosive and shrapnel-laden shells at their enemies from long range. This kind of artillery weapon was very effective against infantry advancing in the open, was rapidly emulated by all major European armies, and--if memory serves--was responsible for more combat casualties from 1914 to 1918 than any other weapon.

Without machine guns and heavy field artillery, World War I would have been dramatically different; they really need to be recognized as innovative, even game-changers in the early 20th century.