Imagine if the food industry could get away with this in their marketing:
"10g Fiber Bars" (fiber bars actually contain only 1g of fiber, "10g fiber" just refers to the fact that it's the 10th generation of fiber bar they've created)
The supplement industry is good at this. You might see a protein bar with 30g of protein, and find out it's just amino spiking[1]
People in the fitness industry were sending products into labs to have them analyzed and then exposing the companies on YouTube.
[1]:The act of using low grade amino acids (usually L-Taurine and/or L-Glycine) to bump up the overall protein content
The comparison to a "10g fiber bar" doesn't work, because in the case of semiconductors the "10g fiber bar" is 10 times better than a "1g fiber bar"
TSMC has sometimes started to use eg. N7 instead of 7nm.. but it really doesn't matter.
If marketing wants to use some metric to convey how good the product is, that's fine, but if the only information being conveyed is the product generation number, they should not be able to masquerade that generation number as a metric. Otherwise it misleads consumers into thinking, i.e. "2nm chips should be able to contain twice as many transistors as 4nm chips!" when that is false.
Because each process generation was supposed to double the transistor density, the names of the processes have been given to correspond approximately with a geometric progression having the ratio sqrt(2): 500 nm, 350 nm, 250 nm, 180 nm, 130 nm, 90 nm, 65 nm, 45 nm, 32 nm, 22 nm, ... , but then the need to round to integer numbers combined with the desire to give distinct names to some process variants that have only small changes in the transistor density (e.g. "6 nm" vs. "7 nm") have lead to deviations from the original progression.
While the transistor density has increased with each process generation, most recent generations have been content with a less than double density, e.g. with a density 1.8 times greater than in the previous generation.
i.e when Ghz stopped being a useful metric (or sole metric) for CPU we switched to other measurements, we did not redefine what Ghz represented.
They really did try to muddy the waters back when CPU clock was the only commonplace metric of CPU speed the general consumer would know about though -- as a couple examples, there was the AMD K5 PR200 which was a 133 MHz part but supposedly (according to the AMD marketing team, at least) competitive with a Pentium 200 MHz -- or the AMD Athlon XP 1700+, which does not run at 1.7 GHz as you might think but only about 1.4.
They did stop short of outright calling it GHz, you're right, but clearly the intent was for the consumer to think that a Pentium 4 1700 MHz and an AMD Athlon XP 1700+ were comparable.
The companies that contract with chip foundries probably know what they're getting. It makes reading industry news a bit more confusing, but for most of us, we're reading it for entertainment, not any practical purpose.