It is widely believed good art-style is the one that is most pleasing to the eye, while this true to certain level art-style has more to it then beauty. Art-style when used properly can do more than just make an anime look beautiful . It can be used as a tool of visual communication and world building. For example the wacky art-style used in one piece perfectly complements its odd unrealistic setting, it also gives a good insight into the characters(Ussop is a liar hence has a Pinocchio nose,Sanji has tall legs signifying his use of legs as his weapon of choice). On the other end we have death note, it has a more subtle and realistic art-style suggesting grounded story,its grey tones are similar to that of neo-noir suggesting the vibes of the crime drama it is. So in this light exploring art-style as a tool that can perfectly compliment and complete the story is some thing that needs to be done.
You may want to consider the works of Masaaki Yuasa, which are all heavily stylized. From Ping Pong (2014), to the Tatami Galaxy (2010), to Devilman Crybaby (2018), the use of color, art style, and dynamic animation style are all vital to the storytelling and, a case could be made, to the setting itself. This is most striking, in my opinion, in The Tatami Galaxy (2010), which uses color and stylized representation of the setting (through photographs on top of drawn panels) to striking effect. – C.W.B. Bryson6 years ago