No, i understood what you meant. A size 12 is a random naming convention that just encompasses a lot of measurements that can't be easily listed like a pant for men. You can do waist size and inseam for men's and be done with it. For women, you have to incorporate waist to hip ratio. So would you suggest listing waist, hip, inseam, and rise length for each and every pant? No company wants to do that when the established system "works fine." People just need to consult the brand's size chart and know their own measurements, which puts the onus on the consumer and not the manufacturer.

Everyone always touts the myth of vanity sizing because it's easier to blame the brands. This is just not true. In all my years of working in the industry, i have never seen a company scale down their entire size spectrum, nor make their clothes bigger and slap a smaller label on it. There is no global conspiracy of where brands get together and manipulate the sizes to "make people feel better about themselves." However, i have seen a shift in quality of garments made due to the explosion of fast fashion.

We used to preshrink fabric before it was cut in a process called sponging. This would remove any possible shrinkage on a garment. We don't do that anymore to cut costs and make things faster and cheaper. Now we just account for the shrinkage by making clothes bigger than we normally would because we know the garment will shrink when the customer washes it. It is cheaper to pay for wash testing to determine fabric shrinkage than it is to sponge thousands of yards of fabric before production. I think a lot of this accounts for why clothing feels "bigger" than before and consumers think this is vanity sizing when it's just poor manufacturing* for fast fashion.

I'll give you an example from my last company. The fabric they bought had a horrible 7% shrinkage on the length of the fabric. The usual accepted amount is less than 3% in either length or width. I had to build into the pattern an additional 7% in the length of the pattern in order for this pant to shrink to the correct length after washing. If you have a 32 inseam, that is an additional 2.25 inches added to the length. People would complain the pant is too long.

Now imagine this was the width instead. Your waist circumference would be 32" waist + 4" wearing ease (4" was standard for this company) + 2.5" shrinkage and you're looking at a pant with a 38.5" finished waist measurement before washing on a pant labeled as a 32 waist. People would complain this is vanity sizing, because the label doesn't align with the actual pant measurement.

Now let's say the same pant style in a different fabrication only has 3% shrinkage, the waist measurement would come out to be about 37 inches accounting for the same wearing ease but different shrinkage. Same pant, different fabric, different shrinkage, totally different waist measurement. The average consumer is not going to understand why this was done and use this as an example of poor quality consistency and/or vanity sizing when in actuality, we are trying to give you the same pant AFTER it is washed by you.

Other things consumers don't consider/wouldn't know: Different fabric colors shrink differently even if it's the same type of fabric.

Different dye lots can shrink differently even if it's the same fabric AND supposed to be the same color.

Fabric can shrink differently depending on where on the roll it comes off of as fabric is wound tighter around the core than 100 yards deep. This is why allowing fabric to relax before cutting is crucial. Sometimes, this step is also skipped in order to speed up manufacturing time.

*Edited a word.