but they did develop a strategy that worked until the invasion of the USSR.

Not really. What they did was to repeat a strategy that had been refined by generations of Prussian generals. Blitzkrieg was a fancy propaganda term for "Prussian manoeuvre warfare." It wasn't a new invention. Now, they get credit for realizing that the tank could be a key component in making manoeuvre warfare viable again, though that largely derived from the shock they experienced at having their defensive lines broken by tanks in WW1. But to their credit, they were at least forward thinking enough to realise that the next war would be unlikely to bog down into a defensive stalemate like WW1 had. However the notion that Nazi Germany was inventing some exciting new method of warfare out of nothing is patently false. In fact the overall level of mechanization in their military was dire; throughout the entire war, many German divisions were moving all of their supply by horse and cart. Also "worked until the invasion of the USSR" basically deletes the War in Africa in its entirety. Germany certainly had some successes there, but also some notable failures, and ultimately they were not able to achieve any of their strategic aims on that front. In short, Blitzkrieg worked until it came up against an enemy that wasn't desperately unprepared for any kind of war at all. That's hardly a ringing endorsement of its success as a strategy and more an indictment of the massive geopolitical failures that allowed the war to occur in the first place.