Customers love the Chinese-founded firm’s massive catalogue of ultra-cheap items, from $8 sundresses to 48-cent bracelets, at a time when inflation has shrunk purchasing power around the world.Like H&M and Zara, Shein has been accused of using factories staffed by underpaid and overworked garment makers, and of causing widespread harm to the environment. Critics also accuse the company of promoting hyperconsumerism and selling clothes designed to be discarded after a few wears — a charge also levelled at its rivals. But what sets Shein apart, analysts say, is a hyper-efficient supply chain and product development process.

“In theory, Bangladesh could probably sell garments for cheaper than Shein. However there’s no ecosystem there to market it, to brand it, to sell it overseas, t…