Shein is now a very valuable fashion company! It has recorded 7 years of 100%+ sales growth, and is now large-enough to be compared to Zara & H&M (with much faster growth). It might not survive (this will depend on their brand evolution), but it is an interesting story.
Shein is a phenomenal growth story. Its (ultra-fast) growth reiterates important lessons on innovation. It also stresses the evolution of new business models and processes.