Man on The Moon.
In the late 2000s, hip hop and music in general was in a confusing place.
Nobody was buying physical CDs because everyone was turning to (mostly illegal) streaming on the internet.
One of the first artists to regularly post on YT, Kid Cudi gained a rabid fan base and pushed hip hop to new realms. His vulnerability when talking about depression and other pain, and the openness in which he recorded about his life gained him legions of rabid fans.
One of the most underrated rappers in hip hop, you can find his influence in basically every artist from 2010-now.
Drake, Kendrick Lamar, and Travis Scott are only some of the artists to say Cudi had a big influence on their work.