Hey @Triston2 welcome to the music boards of the Spotify Community.
Spotify wants all the world’s music on Spotify. However, some artists and tracks aren't currently available. Sometimes agreements can’t be reached with the artist or label or a change may happen in music ownership.
However, please know thousands of albums and artists are added to Spotify every day. If you can’t find an artist you’re looking for, they may appear (or reappear) soon.
In the meantime, feel free to contact Chance the Rapper to ask when he plans to be on Spotify. Thanks!