League of Legends was by far the most watched game since 2016 on twitch.tv.
Top 10 games from January 2016 to April 2020.
Out of the 52 months, only 4 different games topped Twitch for the entire month:
The only time League of Legends was not top 2 of the month was in... April 2020, when VALORANT meteoric rise put LoL at third place.
A lot of thanks to the SullyGnome website for the Data. I used Tableau Desktop to do the visualization.
Link to interactive version here.