Twitch brings in more money than Youtube so probably never. They also don't have to split the revenue in three this way.
We're in a streamer/Youtube personality bubble right now. In the same way that banner ads were overvalued in 1998, these people are overvalued now. It's going to pop, most of these people will be going back to work at Walmart, and the handful that actually have talent will probably get absorbed into something more legitimate. It's like this in case, I looked at a couple of their videos. Sorry, they had no talent. They weren't even funny or insightful. It was literally just some dudes playing video games (badly) with some low production values.
If it wasn't for Carl Sagan's Cosmos streaming 24/7 on Twitch, I'd say that the entire platform was a net loss for humanity.