The history of Soviet electronics manufacturing is fascinating, but there are some huge differences and I actually don't think the private sector is the largest. One is the pace and type of innovation. In the 70s and 80s the landscape was incredibly dynamic and technology went through several huge changes. If you wanted to run a clone of the US tech industry then, you would need a distributed, dynamic effort across many fields and not a top-down directed Manhattan Project. In 2025 we do have rapid technological change, but things are much more consolidated. In terms of strategically important recent innovations I can only think of EUV and AI. That's much more Manhattan-Project-able.
The other difference - which is even more significant - is that China is already far ahead in advanced manufacturing. The US was lightyears ahead of the Soviets in advanced manufacturing, which is what allowed us to win in the 70s and 80s. Now, we're so far behind it's not even funny. Sure, the West still makes some ultra-precise machines for EUV, but look where most of the components in those machines are made...
At the start of the microchip age, the US wasn't that far ahead. The techniques for manufacturing microchips weren't anything special and the Soviets could do so easily. The problem was the top-down mandate to clone, not lack of internal capability.