>>2523748desu senpai
Also, the military under the Nazi regime was portrayed as the leading edge of the fascist effort, and as such received uniforms fit to match the vanguard of the state. For most other nations at the time, their respective militaries were seen more as possible instigators of coups etc. and managed appropriately—tightly clamped and subordinate to the civilian government. With the Nazi civilian government essentially being the military top command, no brakes were pulled on the fascist fashion train.
The garbage state of American uniforms in the past and today more or less represents the concept of civilian control of the military: if the politicians get on stage wearing suits like garbage bags, the military will get in the field wearing garbage bags as well.