In recent years the node names don't correspond to any physical dimensions of the transistors anymore. But since density improvements are still being made, they just continued the naming scheme.
Because the naming is based on the characteristics as measured against a “hypothetical” single layer plain CMOS process at that feature size, this isn’t new the nm scale stopped corresponding to physical feature size a long time ago.
"Recent technology nodes such as 22 nm, 16 nm, 14 nm, and 10 nm refer purely to a specific generation of chips made in a particular technology. It does not correspond to any gate length or half pitch. Nevertheless, the name convention has stuck and it's what the leading foundries call their nodes"
..."At the 45 nm process, Intel reached a gate length of 25 nm on a traditional planar transistor. At that node the gate length scaling effectively stalled; any further scaling to the gate length would produce less desirable results. Following the 32 nm process node, while other aspects of the transistor shrunk, the gate length was actually increased"
That's some pretty bullshit quote-mining there. You stopped right before the important part:
"With the introduction of FinFET by Intel in their 22 nm process, the transistor density continued to increase all while the gate length remained more or less a constant."
I'll repeat it for you see you seem to keep missing it: transistor density continued to increase
This isn't marketing fraud because you aren't being sold transisters like you buy lumber at Home Depot.
Instead, you buy working chips with certain properties whose process has a name "10 nm" or "7 nm". Intel et. al. have rationalizations for why certain process nodes are named in certain ways; that's enough.
>However, even the dimensions for finished lumber of a given nominal size have changed over time. In 1910, a typical finished 1-inch (25 mm) board was 13⁄16 in (21 mm). In 1928, that was reduced by 4%, and yet again by 4% in 1956. In 1961, at a meeting in Scottsdale, Arizona, the Committee on Grade Simplification and Standardization agreed to what is now the current U.S. standard: in part, the dressed size of a 1-inch (nominal) board was fixed at 3⁄4 inch; while the dressed size of 2 inch (nominal) lumber was reduced from 1 5⁄8 inch to the current 1 1⁄2 inch.[11]
Despite the change from unfinished rough cut to more dimensionally stable, dried and finished lumber, the sizes are at least standardized by NIST. Still a funny observation!
So the theory is that Intel and others do this for marketing purposes. In other words, they predict that they will sell more parts if they name them this way instead of quoting the physical dimensions. There is no other reason to do this than for marketing purposes.
That must mean, that this marketing works to some degree. Therefore, it cannot be common knowledge amongst everyone who buys PC parts. Or it might be somewhat known but still affecting their shopping choices. If it was truly common knowledge, there would be no incentive to keep naming them this way?
https://en.wikichip.org/wiki/technology_node#Meaning_lost