The Wedding Cake bullshit was the first time I said to myself "what the fuck am I reading?" That was the beginning of the end for One Piece. So while Wano definitely isn't that bad, I don't think it's fully recovered from that shit-level of writing.
I think the Yonkos ruined the manga tbh. All because Oda thinks any shit writing is justified due to Yonko status. A character running around screaming for cake? Of course, it's a Yonko. It's all good. Although to be fair, we saw glimpses of this with Doflamingo/Dressrosa, but then he still added some interesting shit like Sabo being alive, introducing an Admiral, etc...
The problem is Oda respects some characters too much, so they "need" a long time to be defeated, and in that time any stupidity is justified. He set a precedence with Doffy, and Yonkos had to top it. If Dressrosa dragged out, how can the Yonkos not drag out just as much, if not more?