Yes. Churchill pointed out that prior to '43 the Allies achieved no victories, & after suffered no defeats (though not certain how he classed Arnhem). And you're correct that confidence among the Allies had grown by the end of '43, but confidence doesn't always reflect reality. After D-Day & the breakout, for example, war production slowed in the US because it felt the war might be over by Xmas '44. Then came the Bulge, & renewed German resistance along the Rhine, Hurtgen Forest, etc.
My point here is simply that while the Allies could be confident of preventing a German victory by 1944, a German defeat was not a done deal. As others have pointed out, absent the long-promised second front, & with German troops evicted from Russian soil, Stalin might have concluded an armistice with Germany that would have prevented the Allies from retaking northern Europe.