Chinese e-commerce giants Alibaba Group Holding, Meituan and JD.com are intensifying their costly rivalry in the on-demand fast-delivery sector, with each touting significant gains in user base and order volume. Alibaba, owner of the South China Morning Post, saw combined daily orders on its freshly launched Taobao Instant Commerce initiative and Ele.me food delivery service surpass 40 million within a month, according to data released by the company on Monday. The new service, which has...