The Naruto anime features a truly massive cast of colorful characters, and there is limited screen time for all these characters. That means some Naruto characters will get fully fleshed-out, satisfying character arcs, like Naruto Uzumaki and Sasuke Uchiha, while others will not. Some characters felt unfinished, even after hundreds of Naruto episodes—and that includes their endings, too.
Source：https://www.cbr.com/naruto-characters-with-incomplete-unsatisfying-arcs/
