Your image is as important as your music. At least when it comes to building your brand. Could you imagine releasing visuals akin to a death metal project for a pop record? People interested in your visuals might be sorely disappointed by your album, and pop listeners would probably never find you! That’s why consistency is key. Your visuals and graphic designs paint you and should support the music and emotions you want to convey. There’s a method to visual design, and many more reasons for its importance, so please check out this article if you’re looking for a bit of help.
https://www.mi.edu/in-the-know/importance-graphic-design-music-industry/