The episodes are divided into (often called "Sagas" or "Arcs" by fans). Wikipedia organizes them by story arcs within larger sagas.
This level of detail appeals not only to casual viewers but to media scholars and hardcore enthusiasts who wish to track the production history of Toei Animation. It serves as a database that preserves the ephemeral nature of weekly television, freezing the timeline of the series for posterity. one piece episode list wiki
(Episodes 890–1085): A massive conflict to liberate Wano from the pirate Emperor Kaidou. The episodes are divided into (often called "Sagas"