It wasn't streamers that made ff14 blow up in population or grow considering how boring ff14 streamers are with no personality. FF14 was able to grow pretty well on its own and didn't need the help of streamers averaging 1k viewers or less to bring people in. The only time the game ever blew up on twitch in popularity was when asmongold streamed it for his 2-3 month period that he streamed and once he stopped playing ff14 is back to having 3k or less viewers spread across a handful of people. A game with over a million active daily players and only being able to average less then 3k views a day across a few streamers I don't think it was twitch that built the games playerbase.