I think it's because it is a bit more difficult to storytell in a manhwa than a novel.
Reading Manhwa might be more empty for novel readers especially when we've already read the novel since were more accustomed to being directed by words to use our imaginations than artwork depicting the emotions. It takes skill to do that in art (as an artist myself)
Us novel readers have the tendency to place higher expectations on manhwa adaptations because we've read the novel already and it might mean more to us, that's why some are a bit more critical lololol.
The character development for the MC is lit thoughhhhh

I'm reading the comments sections and all crying...I mean busy cutting onion , which chapter that make you guys cutting onion ???. Why I don't have it ?