Nobody should get the false idea that casino game streamers make a lot of money on the game, its the opposite. I have no idea why this common sense is lacking in some people.
It depends upon the streamer, there are Twitch streamers who are making millions just streaming their gaming session and it all depends upon your niche on how to attract viewers, but casino streaming i have not come across, until you are playing some interesting game you will not attract viewership.