It's not "IC design" that's orders of magnitude more complex. It's "IC implementation" where the complexity lies. Design for test, Logical verifcation (simul

It's not "IC design" that's orders of magnitude more complex. It's "IC implementation" where the complexity lies. Design for test, Logical verifcation (simulation, logical equivalence checks, electrical design rules), Physical implementation (library development and characterization, floorplanning, place and route, signal integrity), signoff (timing closure, electrical desing rules (again), physical verification, OPC) all require highly complex tools to automate. For large designs you will have people dedicated to each individual step because the ways in which things can go wrong -- and the absolute necessity of things going right to get a working chip -- are legion. And there's no substitute for experience to know the right questions to ask. It's like the difference between driving your car across the country and flying to orbit. If you make a wrong turn in your car you can just make another turn or backtrack (edit the source code and rebuild). If don't have the right torque on the tank strut bolts on your rocket, "You will not go to space today". Source: 30 years in the ASIC and EDA industries doing chip implementation and EDA tool flow development.