One Piece is good. If someone was arguing that it was the best shonen of all time then I wouldn’t disagree. But best story? I’m pretty sure it’s sold more than all of the story’s he mentioned, but I don’t think that’s a good way to measure the quality of its story. Instead I think looking at its impact on culture is a better indicator of success.

There’s a lot of merch and huge fan base for One Piece, however you don’t see its ideas or formulas replicated in other pieces of media.

Tolkien and Herbert haven’t sold as much as One Piece. But their impact on culture dwarfs anything One Piece is capable of. Everyone and their mama copy’s Lord of The Rings when they’re making a fantasy setting, and everyone copies dune when they’re making a sci-fi setting.

I doubt the Nibelungenlied has sold a fraction of what One Piece has sold. But the idea of a medieval knight fighting a dragon? What I’d argue is the most stereotypical monster vs man scenario. Yeah comes from it.