Last November, Nguyen Thi Que’s mobile phone suddenly stopped working as telecom companies in Vietnam permanently shut down the 2G network. “I thought of buying a new phone, but I don’t have money,” the 73-year-old, who sells iced tea at a bus stop in Hanoi, told Rest of World in late January. Vietnam’s plan was simple: Offer free 4G feature phones to help low-income 2G consumers adapt to the change. The strategy paid off, reducing the number of 2G subscribers from over 18 million in January 202...