replaced by a better democracy
IMHO Nazi Germany does not equal 'democracy,' nor would the Nazis' downfall lead to 'a better democracy.'
The choices were simple (yet no less depressing):
A) the corrupt, economically-ruined Wiemar Republic wherein even under so-called 'democracy,' the Nazis were still able to seize power electorally in 1932
B) Nazi Germany...need I say more?
C) Communist Germany, and all of the chaos that results in the interwar period from the aftermath of a (possible) brutal civil war, a still-ravaged economy, etc.
All three scenarios are the product of a certain (infamous) harsh post-war treaty created with the sole purpose of blaming the losers and carving up the vanquished Central Powers' territory and colonies to boot, all the while justifying it by claiming that 'democracies' were being established across Central and Eastern Europe (very flawed, corrupt, and ineffective 'democracies' prone to military coups, fascism, etc.) as if that makes it any better.
So IMHO remove Hitler and the Nazis during the war and you either get another ineffective post-war 'democracy' or a series of brutal military juntas and/or Allied occupation.