The BoTB is one that need not have happened. IF the Allies had been prepared to execute a more focused effort against Germany they could have been all the way into Germany before the Fall.
As is typical throughout history, the enemy was underestimated.
After the breakout from Normandy, and the successes of the falaise gap encirclement, the allied armies got what the Japanese had called ‘victory disease’...a phrase used to describe theIr early conquests in the Pacific.
The debacle of market garden should have been a clue that the Wehrmacht was certainly not yet defeated, but it was ignored
Ike, Bradley and Monty should have known that wacht am Rhein, or something similar, was coming. Their arrogance did not allow them to consider that such an offensive could still be launched by the Germans at that point in the war