I'm pretty sure Youtube will overtake Twitch as a streaming platform within a year now. They have implemented the features they lacked a couple of years ago like premium subscriptions for channels. And since they advertise streams in your watch next recommendations in youtube you will get a lot of spontaneous people watching them easily, while you only go to Twitch if you specifically want to watch a stream.

Some video game streamers on youtube reach 50k+ viewers regularly and donations of $10+ just keeps raining in with that audience. That isn't any less than top Twitch streamers, and the Youtube will only grow since it is so much easier for people to discover Youtube streaming than Twitch streaming.

So really I don't see Twitch being a major player in a few years. There is no reason for content creators to stay with Twitch once youtube gives them a bigger audience and more money.