So one (Shein) might be less bad per unit style but encourages more rapid churn. The other traditional model claims fast, but is slower, but has higher upfront build and ship consequences.
I don't think this detracts from your broader point, though -- your specific example just happened to be the unusual exception to an otherwise good rule.
TJ Maxx is interesting in that it is fast fashion but it provides a useful outlet for clothes that would otherwise have been trashed.
So immediately it is a positive since it ensures more clothes are worn than they would have been otherwise.
In the long run, however, by providing those clothes value beyond their original life TJ Maxx helps prop up the finances of fast fashion, so maybe it’s a net negative? It’s not clear to me.