“The Western Allies would have waltzed into Berlin”
Possibly. But up to that point there were a lot of German civilians who were being strung up for cooperating with the US, Brits & French troops. SS dead-enders were as brutal on their own people as ISIS is today.
And the Germans were surrendering whole divisions at a time to the allies as fast as they could to get away from the Russians. Himmler, head of the SS and many senior SS thought that America and the rest of the allies would team up with Germany and fight the Russians. That’s how deluded they were.