Sukuna does die in the manga. The way it happens is quite dramatic and ties in with many other elements of the story, adding depth and tension to the overall narrative.
Sword God Domain 165 was not an anime but a doujin book or manga.
Sword God Online was an animated film produced and broadcasted by Japanese animation company SAO, and 165 referred to a plot or storyline of the film. Although the work is considered an animation, it is actually a special type of manga or doujin work, different from traditional animation works. In addition, 165 could also be a manga, novel, game, or other derivative works created by an author or group.
In the manga, Sukuna doesn't possess all 20 fingers. There are specific story arcs and events where his finger count changes based on the plot developments.
In the manga, Sukuna does acquire all his fingers over the course of the story. This is a significant plot development that has major implications for the storyline and character dynamics.