Throughout history most wars were fought primarily via pitched battles, a very different type of war than the continues trench warfare of the first world war.

Throughout history most wars were fought primarily via pitched battles, a very different type of war than the continues trench warfare of the first world war. Also throughout history there just wasn't much attention for regular people, and they're seriously under-represented in the historical record in pretty much every way. Do you think some Roman general is going to write about his soldiers crying about how horrible war is? Of course not; that would make him and his army look bad. He was much more likely to under-represent his numbers to make his army look good ("we defeated the Barbarian horde of 50,000 with just 5,000 soldiers!" sounds a lot better than "our armies were of equal numbers but we won"). And the soldiers themselves typically didn't leave any records. And throughout much of history there just wasn't all that much attention for these types of problems in the first place. Patton famously slapped some soldiers dealing with shell shock because he thought it was just fake and they needed to "man up". That was probably more or less the typical response for much of history.