That number 333MT means millions of transistors per square millimeter, I get from that linked ars tecnica article. That seems like a much better way to compare different technologies in chip fabrication, because of the well known fact that these gate widths have lots of nuances that impact how many gates per unit of space can be used.

Why don't we just use "millions of transistors per mm^2"? The concept seems obviously useful, until now I never thought of it.