>>279994489 (OP)Nu-shounen appeals to the 3 most influential parts of the audience's body: the brain, the heart, and the dick. And more importantly, it appeals to them in the ideal way for the internet generation.
JJK appeals to the brain. Zoomers have brains as wide as oceans and deep as puddles, and get a dopamine rush from understanding references.
JJK is incredibly good at pretending to be smart. Gege will use physics concepts (that even he doesn't understand) to overexplain powers that are honestly simple enough to explain in a few sentences. This makes the midwit reader feel smart for understanding these powers.
KnY appeals to the heart. Zoomers are simultaneously extremely sensitive, but also have no understanding of actual human emotion.
KnY nakedly presents unrealistic caricatures and hamfisted tragic backstories. Characters will behave in the most idiotic and histrionic way possible in order to create the most tragedy. The story is barebones and the fights follow pro-wrestling logic because all that's actually needed for the audience is to hit emotional beats.
And finally, CSM appeals to the dick. If you've read CSM but have never been exposed to the fanbase (somehow), this might sound like an insane statement. How the hell could Fujimoto's dogshit chickenscratch possibly appeal to anyone's dick? And I'll tell you: mommy issues. Zoomers almost all have mommy issues.
Fujimoto's femdom fetish leaks into every aspect of CSM and has managed to hit the niche that no other shounen has managed.
Also, it's "safe horny". The women are sexually appealing via their role as dominant figures, not via their appearance (I cannot stress enough that it's not by their appearance). So sex repulsed zoomers won't be scared away.
Notice how the blame is always placed on the CSM fanbase for being horny and not Fujimoto for appealing to a fetish.