It gets interesting because the most advanced processes shrink in size (basically Moore's Law), so theoretically the cost of the silicon is cheaper. But of course the big cost is in development and the latest equipment to make all that. Of course we're approaching the size of an atom, so Moore's Law is going to reach a physical limit.
I remember taking classes where the discussion was on how scaling down in semiconductor feature size improves speed. Of course one can maintain the same voltage while scaling down and the performance can theoretically go way, way up. But then the problem is that amount of energy that has to be dissipated just goes way up and it's not a good thing if it just burns up. But the voltage can be cut, the energy used will be lower, and the performance is still better. However, I think there are still some specialty applications where they're willing to do things like liquid cooling. Processors used to come in plastic packaging, but now they come in these fancy packages designed to connect to a heat sink and where there has to be a fan.
Turning Down The Voltage SoC complexity is making it more difficult to combine functional performance with demands for lower power.
semiengineering.com