In a lot of depictions of WW1 compared to WW2, WW1 always seems to appear much more horrific and terrifying, compared to WW2 which everyone seemed much more prepared for. Was WW1 actually that much worse then WW2?
Both conflicts were so global and so complex that it's difficult to establish points of comparison. Tommy Atkins on the Somme in 1916, a doughboy in the Argonne Forest in 1918, and a French poilu on the Marne in 1914 all had very different combat experiences. Much the less the Turkish, ANZAC, and British troops in Gallipoli. Or Russian troops in the Brusilov Offensive. Or askari in Africa.
The same can be said for the many different fronts of WWII. The savage fighting on Guadacanal, Tarawa, Peleliu, Saipan, Okinawa and Iwo Jima certainly come to mind.
It don't think you can universally say one was "worse" than the others. They were both quite awful.
If WWI is remembered as being "worse," I'd say two things are to blame.
WWI was a more shocking departure from the past. It was a huge departure from how soldiers, civilians, and general officers thought war would be fought. The idea of a quick, glorious war of maneuver like the 1877 Franco-Prissian War clashed violently with the slog of trench warfare in the West and in Italy and the bloody, indecisive campaigns of the East.
Post-war media depicted the two wars on very different lights. Most of the iconic WWI films were.made during periods of great skepticism about the war and the social system that lead to it.
Paths of Glory and All Quiet on the Wester Front came out of a post-war sense that the war had been pointless and fought purely for the benefit of callous political elites. While this view was hardly universal, especially amongst veterans groups like the American Legion or the Steel Helmet League in Germany, anti-war opinion was strong amongst artists and intellectuals.
This attitude permeated many of the post-war poems, memoirs, historical accounts, novels and films that have since colored our opinion of the film.
Other films, like the 1970s film Gallipoli were the product of Australian New Wave filmmaking that looked at Britain's role in Australian history in a very skeptical light. You can see similar "war is hell, the English bastards dragged us into it and cocked it all up," attitude in the Boer War film Breaker Morant, which was made around the same time.
By contrast, popular media about WWII has often taken a different tone. Films made during or shortly after the war, like Sahara, Sands of Iwo Jima, or They Were Expendable, showed the war as a worthwhile struggle with heroism and somewhat softened approach to the horrors of war. This is hardly surprising, since many of them were propaganda films. Many of them are still very good films that stand up today, but they have a slant, just like many of the WWI films did.
Even in more visually realistic modern depictions like Saving Private Ryan or Band of Brothers, the war has redeeming qualities. It brings our heroism self-sacrifice in its characters, the "why" of the war is more clear and worthwhile, the enemy is human - yet ultimately fighting for an evil cause.