I big problem afaik was simply the lack of computational power. The USSR was notedly slow and even unwilling to respect and adopt digital computers as a technology. It turns out that planning a complex economy (more or less) by hand is really hard and leads to mistakes!

Khrushchev’s faction reintroduced capitalistic elements, he dismantled the successful policy of shared agricultural machinery between farmers, he attacked the very foundation of the soviet union, he rehabilitated several revisionist figures, he was chauvinistic towards the prc which led to the sino-soviet split.

Too centralized wasnt really the issue, but the increasing elitization of the bureaucracy was.

I’m very fuzzy on memory, but i think it was more like they were prioritizing production of x (say we need 1 million liters of milk or whatever), but not so much we have to deliver x (1 million liters of milk to drinking customers). So on paper production looks fine (cause they did produce it), while in some place sporadic absences occur (of milk or butter or meat or whatever else, random small foodstuff and not foodstuff), and then it rots somewhere else (kinda similar to grapes of wrath, if only for completely different reasons). So like large scale mis-allocation (including temporal as well) in planning. Or not optimizing for worker participation (that’s more related to car production/complicated industrial goods), because you can’t just fire guys, but there is no mechanism to say you’ll have to make cars with 35 man hours instead of 40 man hours (at least i don’t think they did). There were also grading issues of the commodities (steel is not just steel, bolts are not all the same, tomatoes are not just tomatoes) which would explode calculation complexities even further. Like imagine you make every bolt military grade for maximum tensile strength with tempering and shit, and it then used to build either a chair or a tank (actually, things i heard bolts were not that great, with very wide varieties around, but the point from planning issues stands)

(this also all combines with party members on the upper scale starting to inhabit different world shopping wise, more and more after the 70s, so they can’t even check themselves)

Maybe? I don’t think they should have bothered with intermediate commodities (at least without computers) and just gave factories free-er reign on what they do with their local plans, after 50s the factories themselves could figure out how much steel they need for bolts and metal sheets. (but again, i’m fuzzy on details, and maybe they did do that, however, sporadic translations of 5 year plan completions i’ve seen do mentions x tons of steel for some reason).

(i would have said, fuck it, we ball, cut down working hours to 6 by 1970-1980s tbh, to force the factories to adjust to automation)