Many authors create manga stories in hopes that an anime will be made. Videos increase merchandising sales and the author can make money from merchandising royalties. As such, only enough manga story needs to be created to fit into one season of anime. If the author is trying to be efficient, any effort beyond one anime season's worth of story is wasted effort because many shows only get one cour anyways. Thus, the manga was given its rushed ending. This frees the author to work on a different story in hopes that might also have a chance to have an anime.Thank you for translating to the end.
I have mixed feelings about the ending. It was a good stopping point, but they could have easily continued the story.