Not on every piece of clothing you sell.
On the other hand, if the text was just in a language that I did not speak, I can either type this into a translation app myself, or use the automatic translation camera on my phone to identify them.
And sure, I can apparently now do that for those washing symbols too, which is nice... but why is that information being conveyed in a "language" that almost no-one speaks? I'd be just as confused if every item of clothing I purchased had washing instructions in Lojban.
I fully understand why an attempt at standardised symbols was made, being able to communicate that information more compactly would be useful, but it very clearly failed. They're not intuitive enough to learn without third-party resources, and a very very tiny fraction of the population is willing to put in the effort to do so. Just use text.
They are like traffic lights.
Symbols that you never use aren't very useful when all you really need to know is "do not dry", "do not bleach", "wash with like colors". It's really not that big of a deal to put a tag written in English and Spanish to the US, or in French to France, etc.
When artists use English, CAD designers use Traditional Chinese, and factory staff use Simplified Chinese or Vietnamese, and consumers use every language - there's a need for a standard symbol. You have a good point about dry cleaning services too!
The difficult part is that the people through this international supply chain can't type these symbols in emails, or search for them in databases. That's why a Unicode code point should be assigned.
This article looks like it has a general summary:
https://sewport.com/tips-on-starting-a-clothing-line-from-43...
This is not her company, but a job description for a similar role (you'll need to translate from Chinese):
https://www.104.com.tw/job/5cuv8?jobsource=jolist_c_relevanc...
I'm with you, it bears uncanny parallels to the PCB design workflow. Not just the Gerbers, but the component/fabric selection, simulation, design drawings, etc.