Sanji - not gonna lie.. he was pretty cool before time-skip.. and I didn't mind his nose-bleeding and whack even in WCI... but now at Wano, Simpji's seriously getting outta control... it's too much to bear, and I find him absolutely disgusting at this point... I mean, finding prostitutes in Onigashima, are you fucking serious, Oda?
Dragon - I mean, I still like him, but I can't deny that he got a tad more boring now... like every panel we see of him in the manga, it's just him doing nothing... just standing around somewhere, or sitting down in his chair, and that's it.. He's basically Steven Seagal at this point.
Kaido and Doflamingo... not much to say about them, I just dislike them, personality-wise...