KnY's art looks like an autistic middle schooler's sketchbook. Gotouge's art is pencil-sketch chicken scratch and I find the character designs repulsively garish and terrible by every standard. The author seems to have a penchant for adding too many vibrant colors in order to make the characters look "unique" but it just has the opposite effect and they look ugly. It's all over the place with no consistent theme. They don't hold up without Ufotable polishing the art style and hiring all these popular seiyuu to voice these ugly characters.

Less is more and this is especially true when it comes to character designing. There's a reason why DB persevered for 40 years. Toriyama may be a forgetful bastard, but he was skilled at what he did and his designs share something in common with Gen 1 Pokemon in that being simpler and more down to earth can make a design stand out more compared to other more elaborate ones. See Charizard, Pikachu and Mewtwo? They're the most iconic Pokemon and they're all simple in design.

Picrel is probably the worst "professional" art I've seen in recent memory. The fact that the author can't draw ears or faces in perspective is VERY telling. Like, this shit can be learned in fucking high school in art clubs, maybe even middle school or self-taught with some artbooks. Not even Gege draws that badly. Even at his worst, Gege has a solid understanding on panel composition and spatial awareness. Hell, even Isayama improved over the years while drawing Attack on Titan, just compare how his art from the beginning up till now. I'm genuinely surprised how Gotouge made no improvement in their art.