Clearly we need a better measurement. I suggest picking an open core, then reporting the number that can be produced per square meter. Some choices:

https://en.wikipedia.org/wiki/Category:Open_microprocessors

The IBM A2 and the UltraSPARC T2 look like sane choices. Perhaps there is a suitable RISC-V.

So then comparing processes, we could say that process X can do 54255 chips per square meter and process Y can do 83802 chips per square meter.