An infantry man is a pack animal and bunker building ditch digger, that is what he does when he's not sleeping, eating or on watch . You march, and when you stop, you dig, the longer that you are stopped, the deeper you dig, and you carry everything, food, water, iv bags, empty sand bags, mortar tubes, base plates, ammo and sometimes your buddy .
If you're an artilleryman you have a little better standing with the god of war, you get to ride on trucks. But when you stop you still have to dig holes and shove a cannon into place, then you get down to the business of slinging 98lb projectiles around. And St. Barbar help you if the enemy can fly .