It's interesting that Churchill actually opposed the D-day invasion, on the grounds that it would be a bloodbath (which it was). Hitler was being worn down in any event. The sentiment of the time seems to have been "get this over with." Much the same as the thinking that led to dropping nukes on Japan instead of having another conventional D-Day in the Pacific theater.
Since then, we have fought mostly wars of attrition -- just the opposite strategy from WWII. In terms of human suffering in the war zone, it's tough to say which is worse.
From the viewpoint of morale here at home, though, there's little question that our penchant for low-grade, endless brushfire wars has crushed our national spirit. It's not much of a stretch to blame even our most awful domestic problems -- opioids, blind bigoted hatred and mass shootings --
on the "no win" perma-wars in the Middle East, Afghanistan and Vietnam.