I know why I haven't liked One Piece in about 100 or so chapters now (aside from select moments/chapters), it's the art/cinematography, it has no presence to me, I'm not drawn into the world anymore, hope Oda can get back to his previous level one day.
Edit:
(Obviously it's the story as well, but the art is a major boon still)
If by art you mean narration, then it's linked to the story itself yeah. But I don't see anything wrong with the art in itself.
Honestly, I kinda hate everything that has happened since the Vinsmokes were introduced.
And the narration of the 3 last chapters are so bad. Everyone noticed it when the four commanders appeared, it looked like a random apparition of Fairy Tail villains. But even now, I don't get how we go from "protecting a random island from Pinkbeard" to "sneak in the Reverie". I feel like we skipped a chapter at least. Just, how did Sabo get there ? It deserves at least a panel.