Many years ago I sat next to the CTO of Broadcom on a plane. We struck up a conversation and when I learned he worked for a chip designer I asked the question that I assumed was the most difficult part. I asked how the engineers laid out the circuits physically on the chip. He laughed and told me the engineers write software that defines the parameters and functions and the software lays out the chip (I know I am oversimplifying). I was dumbfounded to learn that hardware design was really software development. Today I think Google has an open chip design effort where you write chip specs in Python (from memory).
They even have their own languages for coding the chip logic ( Verilog is one).
My partner did chip design and layout. The used a tool call magma (We have some mugs from a conference she went to) but they got bought by synopsis. Very expensive, very specialized software
This was probably not true many years ago, or at least was a simplification. Even with some automated routing, there are many subtleties like high frequency electronics; not trying to have your radio equipment routing through your power supply, etc.
It is a mix: digital logic is almost entirely laid out by machine, but analog circuits and the underlying logic cells (as well as certain specialised digital blocks like memories) are a lot less automated. The most expensive part isn't doing that: it's doing the validation and simulation of the design so that it'll have the best chance of working after you've spend 5-6 figures and many months on actually building it (and then there's the cost of testing it in reality and figuring out what isn't actually working and how to fix it: the first batch of chips still extremely rarely works).
