I was an anti-tanker by training. From my understanding, from looking at tanks as targets, the German mistake was in gross over engineering in areas that really didn't matter (such as gears and whatnot made to long out live the life expectancy of any armored vehicle on a battlefield) and over complexing the drive train.
The attrition on German heavy armor was ridiculous. I don't recall the exact numbers, but iirc, it was somewhere in the area of 25% + didn't make it from the lagger to the fight in average engagements. That was just from drive train breakdowns.
Something that is almost always overlooked in the discussions on WW2 Soviet armor is the absolutely craptastic optics in the gun sights. Many gunners found it more effective to punch out the glass and stretch wire across the sight tube to use as a reticle.
Summing up the Germans' efforts in armor design from mid to late war, it always seemed to me the Germans were more interested in building propaganda status pieces, rather than effective fighting tools.
Well, that the loving fuhrer decided that the factories would focus on producing tanks. This is great in theory and on paper as more tanks are produced. Unfortunately this also meant that nearly no spare parts were made. Which meant that even failures which could be fixed easy in field would be hard due to lack of spare parts.