Dressrosa was the worst weekly release, dreadful pace, abysmal panel time distribution. We really spent a quarter of the arc watching characters like Jeet and Abdullah ride some bull on top of Pica and other similar events. I have yet to even revisit that arc because of how much it haunts me.
WCI had an amazing fight, a great theme, great visuals, but the plot armour, along with Sanji and Big Mom completely ruined that arc. This should tell you how shit it was because those are 2 of the biggest players in that arc if not the biggest. Oh and the entire Vinsmoke family is one of the biggest mistakes in this series, terrible designs, terrible characters, terrible backstory, just a colossal failure.
Wano as flawed as it is, and it's probably the most flawed, was still important/meaningful enough for me to justify reading it.
FI is also complete ass cause of the antagonists. If not for the fisher tiger flashback that arc would be a 2/10. Honestly I might just go with FI even though I'm aware there might be worse written arcs.
Man, I actually can't decide there's so many bad arcs lmao. I thought I would say WCI and call it a day but atleast it has plenty of reread value.