They used to refer to the smallest features, but they haven't had any real meaning for a long time now. The names of the nodes don't correspond to any physical feature of the actual transistor anymore.

Who cares? It's not like most of us are designing logic gate cells for chips. The transistor dimensions are irrelevant to us.

I really don't understand why this keeps getting brought up. It's not even an interesting fact.

When the chip manufacturing industry started finding other ways to increase logic density, improve timing, reduce power consumption, etc, they just started bumping down the "nm" number to indicate the improved performance, in a similar way as reducing the transistor gate length would have done before. Simple as that.

We should really measure this based on density for some basic repeated structure, or something like that. Adder-density or something, haha.