It's more rather that the USSR and China copied Western tech to catch up because of how backwards their development used to be. They started from feudal conditi

It's more rather that the USSR and China copied Western tech to catch up because of how backwards their development used to be. They started from feudal conditions and had to catch up to capitalism and promise to surpass it into the Marxist next phase of socialism and communism. The two states therefore had a strong focus on industrial development. However, I think that the decline of the USSR was in how they failed to capture the advantages of international trade (like Cuba or North Korea remaining in economic statis). The Chinese in the Deng faction instead chose to partake in international trade even if it meant that they had to become the sweatshop of the world. After that industrialization, they now under Xi can be pompous and choose to push their weight around given the power of their trade and autarky. Holodomor (and the Chinese famine too) are of course tragedies to be wary of. I think one reason they occured was due to the planners being unaware of the economic incentives and effects on individual actors of their rapid industrialization plans. This resulted in the USSR then launching a war on kulaks and the Chinese launching a war on Westernized intellectuals to make them comply with their plan.