I think the "big" names in terms of streaming on Twitch in a music capacity started with Deadmou5, he has been at it for years. Tpain been making a lot of music there too, and since the quarantine, Mike Shinoda has been making music there every day as well. He just completed an album (Dropped Frames) that he did entirely on Twitch, where he had a contest of bringing fans onto a record (only one with vocals), and decided to mix all the finalists into the completed product.
Not necessarily my type of music, but that sort of stuff, if it succeeds will probably gain the eye of more people from the entertainment industry. Now adding Logic to the mix, certainly looks like Twitch is trying to attract more mainstream entertainers.
Streaming is not going anywhere, but would not be shocked at all if in five years, the top recommended on Twitch is starting to be more like YouTube is now. Mainstream entertainment/entertainers at the top. Fully expect the Twitch TOS to become stricter and more enforced in terms of what content/actions they'll allow people to get away with as they "clean" up their site. When they get the Watchparty function working properly, live airings of late night shows and the likes won't be far behind.