How did the Germans, despite their competent leadership and planning, make the critical mistake of poor preparations for the cold climate before the invasion of the USSR

The poor preparation of the Germans for cold is mostly a propaganda invention. Germany needed some way to excuse their defeats to the public in winter of 1941 and decided the fierce Russian winter was to blameRussian winterThere is some merit in that, Russian winters can be brutal and Russian forces were better prepared for the event. However during most of the winter of 1941, Russian forces were on the offensive and lacked adequate logistical support just like Germans did. That meant Russians did a lot of marching during that winter, as well as sleeping outside, whereas Germans could count on prepared, warm places to sleep in. I find it likely Russians lost more men to the cold than Germans did.There were problems with winter clothing to the Germans sure, but this was not for the lack of preparations. Germany had a stockpile of winter equipment in depots across Poland, ready to be shipped to the front line. The main issue was that they had to choose whether to supply the troops with ammunition or with clothes and Soviet offensives forced them to pick ammunition more often than not. That caused a good deal of problems, the distances were vast and the amount of equipment to be moved was unprecendented and above and beyond what the Wehrmacht could hope to handle.That was what really saved the Soviet union in 1941. If Russia had the road network of a similar density and quality France had then Moscow likely falls, or it at least surrounded and besieged in late summer of 1941.