Huawei is China's—and formerly the world's—largest smartphone vendor, and over the past 18 months, it learned an important lesson: the company can't rely on the US supply chain. In 2019, the US government banned US exports to Huawei, which cut the company off from access to most chip and software suppliers. Building a phone is hard without access to key parts and apps. Huawei's latest Q4 2020 numb