the number of nanometers used to name process nodes (see the International Technology Roadmap for Semiconductors) has become more of a marketing term that has no standardized relation with functional feature sizes or with transistor density (number of transistors per square millimeter).
Although the so-called process node is still named in nanometres, it hasn't represented the actual transistor size in quite a while.
https://en.wikipedia.org/wiki/Semiconductor_device_fabrication#Feature_size
Pretty interesting, thanks for that link