Well inked lineart doesn't only have to look nice, but also aid in making your scenes easier to understand.
Traditional black and white manga rely on clear lineart much more so than colored comic books.
For example, while very fine and sketchy lines may suit landscapes and objects, they make characters appear rather lifeless and hard to relate to.
A bolder, cleaner lineart on the other hand makes landscapes look stylized and unrealistic, but it gives characters more personality and makes them stand out.
By combining two or more types of lineart (you can use different pens and brushes to do so), your scenes become visually easier to grasp and nicer on the eye.
