I wonder how significant it is that there is all this worldwide expansion of chip making factories just as we get to 3nm architectures, I say that because there aren’t very many nm’s left, what happens when we get to zero?
It's mostly a marketing term right? They might do something like 0.5 or add some letters like X or whatever.
I think so. IBM recently produced a new "5nm" chip. In reality the physical size is closer to 24nm, if I remember correctly. The numbers you hear don't literally mean the physical size of the transistor, it refers to something else.