I believe it wasn't exactly styrofoam, but was rigid and low density. This suggests probably an aerogel: https://www.lanl.gov/science/weapons_journal/wj_pubs/17nwj2_...
But I'm not sure I agree that using more generic components should make the technology so expensive.Especially if there was a demand for that.
So using a versatile mcu, with lots of ram/flash, dual-core(big/little) for low power, and a rich set of peripherials, together with some affordable fpga, and some greenPak programmable gellybean logic, and some voltage conversion parts could be good building blocks for digital electronics.
As for Analog, programmability exists too, in the form of via-programmable analog chips(laser programmable at the factory, I think for volumes of few thousands). That still doesn't cover high-performance parts but that would fit many projects.
As for power electronics, I don't know much about that, but I do wonder.
This is an interesting subject. If you're building something very critical, you need to track precisely where your components come from, where the material for those comes from, where the raw materials came from etc. This is also one of the reasons why nuclear power or medical technology are so expensive. We have gotten used to having extremely low cost hardware, but that is because it's produced by obscure long subcontractor chains spreading all over the world, intense competition, constant optimization and churn.