Yes, the prize like that is difficult to win so we can only think that the streamer have a big luck. We also don't know if that is setting from the casino that let their streamer win big money to attract people to visit the site and playing gambling on there. If the audience can be wise of what they watch, they should not try to follow what the streamer do because that can make them lose too much money. While we don't have a big capital to playing gambling, we must limit our funds and not playing gambling too long.
I see streamers more like influencers. How do I know them? Most of the time when you check their bio, there must be a referral link and they make sure it's short because they know that people don't like to click links, so they shorten the url so that people don't see the website they will be redirected to. This behavior is what many influencers do to make money from gambling and not what they spend in gambling, some of them don't care about their subscribers.
There was one guy that was trying to enlighten gamblers about the manipulation of casinos and how they promote new casino websites where they will be given a special login for them to bet but the back end is doing nothing but it will be part of the casino but they neither win or lose. This is how many of them fools their followers with their followers and say they are given some private classes but we know there is nothing special about those private classes.