Chinese brand Vivo took the leading role in the country's smartphone market in 2021, according to market research company Counterpoint Research. With a market share of 22 percent, Vivo lead China's smartphone market last year followed by Oppo and Apple, with market shares of 21 and 16 percent, respectively. Realme witnessed a year-on-year growth of 379 percent to grab 3 percent of market share last year, becoming the fastest growing brand. All the other brands accounted for 4 percent of the market share in 2021, during which full-year smartphone sales declined 2 percent year-on-year for the fourth consecutive year. Let's…