It would be cool if you can sync the streams. Either from the streamer or viewer.
If, for example, 4 streamers play something together, you could watch everyone at the same time. Would be a cool novelty, which has never been possible before.
As an example Amoung Us: You could see where everyone is at the exact time, which would be cool for other moderation games as well.
If there is a difference of 10-20 seconds between the streams, it is not possible to follow several at the same time.