Are you serious? Dude completely changed hip hop, multiple times. Absolutely massive innovator in production style, and basically created the chipmunk soul style of production. He would be considered one of the most important figures in hip hop even if he never even released an album, just for his production work with Jay Z.
The College Dropout was a landmark record for hip hop, for many reasons.
Then he had another landmark record in 808s, popularizing the use of auto tune and melodicism in hip hop (not a trend in hip hop I loved, but you can't deny the influence here).
Then he had another landmark record in MBDTF, bringing hip hop to the absolute front and center of pop culture. Completely bombastic and basically the HH equivalent of a stadium rock album. Collabs with Justin Vernon and samples from King Crimson brought in fans of rock to hip hop like never before.
Yeezus is slowly showing itself to be more and more influential as well, though this one was delayed a bit but we're seeing more and more high profile disciples.
Anyone that denies the influence of Kanye is completely ignorant. He's a piece of shit, sure. But his music has been incredibly important and to deny that is absolutely ridiculous.