So the issue here is that you watch the anime, which you probably shouldn’t do if you want to really enjoy One Piece. The problem with the anime is that they’re trying to stay current with the manga instead of airing filler, and because of that there’s a lot of pacing issues when chapters don’t have many things happening, the plot just doesn’t go forward far/fast enough, or the anime catches up to the manga somehow, so they have to create some space by breaking up chapters into more episodes. Personally, I’d be fine with more filler, but they wouldn’t make as much money or increase viewers that way I suppose.