Why Hetaoni have an ending?

You're likely referring to the popular webcomic Hetalia: Axis Powers, which doesn't have a definitive ending. While the original webcomic creator, Himaruya Hidekaz, has stopped updating it, the series continues through other mediums like:

* The manga adaptation: The manga continues the story, adding new chapters and storylines beyond the webcomic.

* The anime adaptations: While the anime series followed the webcomic closely, they also added original content and diverged from the webcomic at times.

* Other spin-offs: The franchise has expanded beyond the webcomic with spin-off mangas, games, and even a live-action stage play, all with their own storylines and endings.

Therefore, there is no single ending to Hetalia as a whole. The webcomic itself remains unfinished, while other mediums continue the story in various ways.