Fillers. Most large mainstream animes have them, animes with at least 100-200+ episodes. They are just episodes or even sometimes entire arcs that have nothing to do with the original story and add nothing to the actual plot. Fillers are completely useless.
Fillers are made when the anime has been animated up to a recent arc, usually one or two arcs behind the source material. Sometimes the anime actually catches up to the manga in the middle of the arc, which forces the animators to create filler episodes. It certainly does make sense as to why fillers are made but they are still stupid. Instead of having a filler, just take a break. Give both the animators and the fans a break from the idiocies that are fillers. No likes breaks in the main story line but certainly no one likes when the anime just goes on random tangent it didn’t need to go on. Of course we’ve heard of the filler animes, Naruto, Bleach, One Piece, and many more. The big three do fillers in the most annoying way possible. Naruto and One Piece have fillers episodes in the middle of story arcs. It totally takes away from the experience of watching. Bleach is even worse, it has entire filler arcs, a bad at least 30 episodes in the middle of one of the greatest fights in the anime. They have weak stories, are executed in a poor manner, and are overall not enjoyable by anyone.
Fillers are made to keep up with episodic demands and the upkeep of income. Animators have to release weekly episodes to keep up with the demand and income. But, it’s not appreciated by the fans. Most of people don’t like filler. Are there people who do like fillers? Of course there are, you can certainly like filler but personally I don’t and most of the people I have spoken to don’t either. But, I digress. Fillers are stupid because they take away from the original storyline at the cost of continuity and contentment of the watcher.