There's a very simple explanation - namely USA had untouched industry with already big investment into computer-related areas by the end of the war, while europ

There's a very simple explanation - namely USA had untouched industry with already big investment into computer-related areas by the end of the war, while europe was heavily destroyed, and USSR not only got heavily hit in industry, agriculture and manpower, but also even by 1991 didn't really stop being on a crash build-up program due to Russian Empire being, well, a shithole[1]. The trade war component of Cold War meant that while cooperation (or plain exploitation) in the west made certain stuff more available, that didn't happen to East of the divide, even disregarding issues in how industry was run (which aren't necessarily due to "socialism", but get associated with it). [1] In Poland, the eastern side of the country is still noticeably less developed, with lower development marking the parts that were in Russian Partition - and that was one of the (on average) best developed regions in Tsardom.