There are, in fairness, plenty of reasons why the City might be reluctant to embrace the Chinese fast-fashion giant Shein. Its disposable fashion ravages the environment; it encourages rampant consumerism; it has admitted to finding child labour in its supply chain. Here’s the problem, however. The London stock market is in such a dire state that it can no longer afford to be picky – and if it turns this one down it will condemn itself to irrelevance.