Ngl Toriyama and Mirua had me concerned for Oda, and this isn't helping :
One PIece might have been over by now and Oda would be able to chill if he didn't have this habit of introducing and focusing on 150 irrelevant side characters every arc.
I will stand my ground that Dressrosa had no business being 100 chapters long when it was just another arc of Luffy beating a warlord and we never needed to have NINE scabbards.
Ever since he couldn't finish the chapter where Ginny died (art wise I mean) I knew it's time for him to start making notes for the chapters in the future in case he dies soon or becomes too ill to keep writing
 
I blame his post-timeskip editors.
A good editor's job is also to put a stop to the unecessary stuff.
The thing is that One Piece became extremely popular right before the timeskip, and the series was basically too big to fall so they had young & newbie editors that are One Piece fanboys to oversee Oda and were unable to reject any of his ideas.
The biggest problem was one pieces success during ennies Lobby Impel Down and Marineford.

These arcs became the bones of what Oda builds his current arcs in. The whole run piece scene started with Impel Down and Marineford. This also was the origin of Luffy Piece as well as minor characters getting major shine.

The popularity of these arcs made the editors likely think that this is what people want, run piece with lots of big scenes and big character casts. And because of the popularity of ennies Lobby, one piece became a much more battle centric manga where they don’t even explore islands anymore like we saw in arcs prior.

Because of this we have a generic battle Shonen with too many side characters clashing and taking up panel time
 
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