They actually do imho. The streamer's reward is actually the hardest to get, and it's the lowest reward too (considering what you have to do to get it). You can't go afk in the 2hours. You need to be constantly playing if not you'll get reported for abusing.
It's also highly dependent on whether or not there are rooms to play in. Most of the time i don't even hit 2 hours because there isn't any gameplay. Whereas for example the daily rewards, you can afk and get the rewards.
Also, streamers contribute more towards the server. Yes i understand that there are barely any views. But it's definitely better than if there wasn't a stream up for the game.
And when i say gameplay i mean actual gameplay. Not sitting in training or skillmaps. Those do nothing for the server if you're streaming.