Why were so many people that died in World War one privates?

Answer 1

Most soldiers are privates, the lowest rank in the army, the bottom of the pyramid. The higher you go in rank, the fewer are the men holding the rank. And, the higher the rank, the farther you get to be from the actual nasty business of the army, killing and being killed. Privates have to go where they are told. The old term is "cannon fodder". In short, there were many times more privates in places where a man was apt to get killed than there were majors or colonels. There were captains there, but only one for every two hundred privates. There were a few more lieutenants, and still more sergeants, but most men at the front were lowly privates.