The claim about fast fashion not lasting long is not necessarily about quality or durability. It’s more that the business model is about chasing short-lived trends such that the clothes are thrown out by stores or consumers after a short time because the trends they were following passed.
Yep, and "fast fashion" originally meant quickly copying catwalk trends and getting them to consumers quickly. It's now somehow morphed into meaning clothes that are quickly thrown out but without anyone actually demonstrating that is actually happening.
> quickly copying catwalk trends and getting them to consumers quickly
That's not much morphing, the goal is to have clothes that are quickly obsoleted for people who can now immediately keep up with the trends. Those people can be a minority of their customers but buy far more by volume, don't wear clothes until they wear out, and need to dispose of out-of-date clothes. If they push enough consumers to fast fashion then there is a vast excess of used clothes that need to be thrown out.
I must say: things from H&M hm have regularly been holding up longer than other way more expensive brands. Sometimes they don’t really fit right anymore, but no holes or stitches that come loose.
