I thought one of Carver Mead's main motivations for developing VLSI with his students was that at the time, designing and fabbing a bespoke single silicon devic

I thought one of Carver Mead's main motivations for developing VLSI with his students was that at the time, designing and fabbing a bespoke single silicon device (comprised of networks of many transistors) to implement a particular "program" was much harder than designing and building the same functionality from a "macro-network" of pre-existing, off-the-shelf, catalog transistor devices. I.e., it was easier to implement the logic for a traffic stop-light or an electronic calculator or a television remote-control by assembling a circuit from off-the-shelf components than it was to implement the same transistor logic in a single integrated circuit. It was definitely possible to do the latter in the early/mid 70's, but not as economical. Your comment points out that SoCs are the modern pinnacle of implementing everything "in silicon" - yet are we not also still implementing "the other half" of the system with circuits of many off-the-shelf ICs? I.e. one IC is CPU+Memorycache, another is RAM, a third is wifi module, etc.