Hip hop is huge on Spotify, where it struggled for radio play and sales before because commercial radio is so conservative (in the sense of risk-averse). Then there's the whole Billie Eilish thing: huge on Spotify, almost no radio play at all.
On the other hand, there are Billboard 100 artists who are more or less absent from the streaming landscape. Some sell lots of albums but aren't on the streaming charts at all.
It's probably not as simple as saying that streaming is only good for established artists, but bad for the long tail. For some of the previous long tail, it's been very good. And for some of the oldies, it's been phenomenal - Spotify enables them to monetize their back catalogue with near zero promotion or distribution costs, year round.