the difference is that most shonen that get big have something special in them. Kimetsu no yaiba focuses on the beauty of human life and struggle, short and weak as it may be, Jujutsu Kaisen has conflict of how to keep going despite your own weakness against established power and a world about to collapse, JoJo's Bizarre Adventure has really unique abilities and weird plot points, and so on. Sure, there are 30 imitators for every unique one, but that's better than thirty batman comics all running at the same time.
the difference is that most shonen that get big have something special in them. Kimetsu no yaiba focuses on the beauty of human life and struggle, short and weak as it may be, Jujutsu Kaisen has conflict of how to keep going despite your own weakness against established power and a world about to collapse, JoJo's Bizarre Adventure has really unique abilities and weird plot points, and so on. Sure, there are 30 imitators for every unique one, but that's better than thirty batman comics all running at the same time.