And you are wrong.
Even if you hate some mangas, you still have other more original works to choose from... Oh you are tired of isekai, go read romance, or maybe some battle manga, or...
All HARDLY will share stuff between them, like, you hardly will find in a HS rom-com things you find usually in isekai (magic, adventurers, monsters...).
What about manhwas? Well, it doesn't matter what the core theme of the work is: urban cultivation, system, sects... chances are they share most of the shit: "jumpy plot", arrogant MC, CCP simp MC aka:"patriotic", censorship, Heavenly silvered moonlighting tetra finger shadow shot- type of names...
So no, manhwas aren't better, perhaps some manhwas are better than the average manga, but at large, manhwas are still shit compared to them.