Watching streamers gambling with a ton of money is a complete waste of time if you ask me since the funds that they use are usually supplied by the site that they are gambling in which implies that the risk factor here is zero.
It's a clever tactic used by many popular gambling sites to attract gamblers for sure, but trying to replicate their wins is silly due to the difference in the risk factor between the streamers and gamblers.
I guess some people watch these streams for fun which is the silver lining here.
I believe people watch not because they think it is real gambling, but because they just like to watch people do stuff. I mean look at all the gamers, I can buy the game and play it myself as well, and in this day and age there are so many places that I can go ahead and find other people to group up and play together too, and yet I do not do it at all.
This is why I believe that we shouldn't really be expecting anything big out of this, it is not about the real money or fake money, it's about the community basically. If you watch someone then you sort of belong to their community and if you chat enough, you will get to know other people and make friends, that has always been the real reason for twitch.