For years, environmental advocates in the West made real progress cutting off supply chains in Southeast Asia that violated ESG standards. But thanks to the Chinese market, many are back — and stronger than ever.

Brands have long relied on social auditing companies to monitor their supply chains in China. But between the industry’s own flaws and a changing political environment in China, many say these reports aren't reliable. With the Uyghur Forced Labor Prevention Act now going into effect,...