The problem I always had with the Naruto fillers is the fact that they contribute nothing to the series. I know shows tend to do fillers but c'mon why don't they at least do some background story telling? I wouldn't really mind fillers if they told you stories of the founding of konoha/ the other villages with some more details than what we currently know. Or some stories about characters that sort of just dissappear without me getting me head wrapped around their importance. A bit like the short filler arc they did with Nagato, I didn't really mind that one.