“Looks bad” is completely subjective. I think you just don’t like Hara’s art style. Not liking an art style is not the same as the art itself being bad.
I have always personally thought Kingdom’s art is stunning. The manga looks jank in certain instances, but I’ve never read a manga that was completely stunning in every single instance. Even Miura’s and Murata’s art is not always incredible, there were 100% moments where the art looked less than stellar. Overall Kingdom’s art is just Fuego imo.
As for level of detail, Hara is literally the goat in that regard. I’m beating a dead horse but no mangaka ever has achieved this level of detail in a weekly manga while taking absolutely minimal breaks.