You refer to all as "repressive" as if there were no varying levels of repressiveness. But there were, and the bodycount as a percentage of the population is can be a good way of comparing represiveness. Germany and Italy were also socialist to a degree, but they didn't take central planning nearly as far as the Soviets did.
Do you actually know how the German and Italian economies worked under fascist rule?
Nazi Germany was a fucking nightmare. Hitler was a Social Darwinist, he fostered needless internal competition at every level. At least under the Soviets, when a decision was made on what to do and build,
that decision was implemented on pain of gulag. Under Nazi Germany, you'd have it disseminated to a bunch of different people who'd all try to implement it in their own way, causing a cartoonish amount of waste, mismanagement, and general loss of time, materials, and money. Half the reason the Wansee conference
happened was because Hitler needed all the various bickering bureaucracies of the Nazi regime to work together to wipe out the Jews, so he had Heydrich scare them all into compliance.
If anything, the command economy of the USSR worked
better than the Nazi one, especially under wartime conditions. And that's saying a lot considering some of the comical bullshit that went on in early Soviet Russia. (I read a book by a guy who emigrated to the USSR, worked at Magnitogorsk, and later returned to the USA, he said that there was one place where they had three tractors, and the State said they had to have 3 tractors. But 2 of them broke down and they didn't have spare parts. So, IIRC, they used the broken ones to boil potatoes for snacks and just cannibalized them for parts for the third. They got in trouble for only having one operational tractor, so, if I remember correctly and I could be wrong because I read this in junior year when my mental state was collapsing, they put the parts from the working tractor back on the broken ones (which had by this point had chunks carved out of them to better serve as makeshift stoves), and had
zero working tractors)
Don't overlook Kleptocracy.
Yeah, well, I figure that if they were
really lucky, the Russians under White rule
might be able to reach the efficient, free and egalitarian heights of Nationalist China.
(sarcasm intended)