Kanye? Drake? Kendrick?
All three of those artists have changed the music landscape to some extent, arguably as much or more as any of the artists listed already (except maybe The Beatles).
Listen to 808s and Heartbreaks by Kanye and then listen to any #1 hip hop album from the past 10 years. Almost all of them were influenced by Kanye, even Drake, the biggest musician of the past 10 years, has a remix of a song off of 808s on his first mixtape.
In the way that Nevermind caused grunge to go mainstream, 808s has inspired the generation of artists who made rap the #1 genre in the US. People like Lil Uzi Vert, Kid Cudi, Juice Wrld, and pretty much any other new artist say they got a ton of inspiration from Kanye. I can't think of much more cultural impact than being the main influence on the largest genre in the world.
And Kendrick caused real political discussion with songs like Alright, and had people protesting in the street with his lyrics on their signs. Whether or not you agree with the message, I'd say having your lyrics be part of the largest protests in history is culturally impactful.
Anyone in here saying there hasn't been a musical cultural icon since Kurt Cobain is not paying attention to the current landscape of music. Their parents rolled their eyes at Jimi Hendrix or Nirvana, and now they're rolling their eyes at Kanye and Drake.