For most consumers I'm not sure COGS is something that they are aware of.
The big takeaway from understanding COGS is using that to understand fast moving and disposable goods and merchandise.
In the UK a recent (last decade) thing has been fast fashion, Primark and the like are leaders at this. It is possible to purchase a pair of straight leg jeans for GBP 12. Understanding COGS means you can quickly realise that the absolute maximum amount spent on materials and manufacturing is GBP 4.
An awareness of COGS reveals to buyers unethical manufacturing, low quality, and essentially planet damaging goods and merchandise.
On a more individual level, i.e. the Beats headphone example in the article, it can also reveal when you're being ripped off. Where what you're buying isn't the goods as much as it is the sticker on the side and the status.
COGS may not be a secret to most people on HN, but they're an unknown part of the magic of how global commerce works to the majority of people.