One Piece has had some interesting things to say about the nature of being human across the series. A lot of it is tied up in Chopper's arc, but in general Oda is also very robot positive. Like, Franky has some angst during the Water 7 chapters, but it's not about being a cyborg.
Despite having all his organic matter replaced, Kuma is able to retain his humanity through his love of his daughter. Characters who believe themselves as "transcended"--usually to some sort of godhood--are the people who have cut themselves off from others. It's this self-aggrandizing isolation that's portrayed as truly monstrous, when more traditionally monstrous characteristics are the most human of all because of their continued ability to love and make bonds with others.