World war 2 was considered to be worse due to high casualty rates and other components like the Holocaust and mustard gas etc.....
hope this helps my friend.
World War 1 was worse because it was the first timr that happen war so everyone at first though that it will be a easy war,but than things compicated for soldiers and family,WW2 was not worse at all because there where new descoviries and people have experienced that.