The law is definitely not dead in One Piece. It exists in various forms and degrees, and its enforcement or violation drives many of the story arcs. The struggle against injustice and the search for true justice are ongoing themes related to the law within the manga.
The One Piece manga is far from over. The story is complex and expansive, and there's still a lot more to unfold. The author is continuing to create and surprise fans with new developments.
The ending of One Piece is a complex and epic conclusion that ties up loose ends and brings a sense of closure to the long-running story. But without spoiling it for you, it's a mix of emotional moments, big battles, and revelations.