The 21 YouTube channels that gained the most subscribers in 2019, from T-Series to MrBeast
10:50am PST - December 23rd, 2019 pewdiepie - Business InsiderThe YouTube channels that gained the most subscribers in 2019 show the platform's current trends and surging areas. Business Insider looked at the 21 fastest-growing YouTube channels – which all gained over 10 million subscribers in 2019 – according to data p…