Elon Musk has declared he wants to transform Twitter into an all-inclusive app that people can use for payments, news and food orders. “Buying Twitter is an accelerant to creating X, the everything app,” Musk posted in October, weeks before completing a $44 billion acquisition of the social network. Advertisement He later said that Twitter could be like WeChat, the popular Chinese app that combines social media, instant messaging and payment services. But nearly six months after Musk took over Twitter, his ambitions for the platform have remained mostly that — ambitions. Advertisement Although the billionaire has made dozens of...