Generally, most anime get 12 or 13 episodes, and that is it. Occasionally, a show might prove successful enough to warrant a sequel, and they tend to be either shonen, isekai, or (maybe) romance stories. Once every few years, an anime becomes a weekly fixture, releasing content for seemingly ever and producing hundreds of episodes. While usually great for binging, these shows are designed to be consumed over what feels like a lifetime. Sometimes, a short anime that can be completed in a day is just more enjoyable.