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.
There are more prominent examples on YouTube. One fella which has over 300K subs gets 4-figures in sponsored funds per video, and one of them is Roobet.