Here we go again.
The quality of the anime isn't really bad, and whoever says this is tricking themselves.
Let's compare it to My Hero Academia, a series some people use to argue in favor of airing seasonal. In the latest cour/arc, there hasn't been a single episode that matches the quality of this week's One Piece episode, actually 849, 848 & 847 are also better than what My hero academia offered in its current arc.
I still don't believe that some people don't realize why they don't like some of the episodes themselves. Episodes 847 & 848 did a pretty good job at adapting the manga content of these chapters, it's just that some these people didn't even like the chapters those episodes were based on. But for some unkown reason, they assume it's the anime's fault it didn't make them excited over what they already didn't like.
However, I don't deny that the anime could be improved upon a little further, but it's really not bad at all.
–- Update From New Post Merge ---
Hunter x Hunter was week to week for like 150+ episodes, and it looks great and is well directed. It’s possible; folks just don’t like Toei because they rarely make the effort despite the huge profit that OP brings.
No, Hunter × Hunter (the 2011 iteration) was mechanical at best, it almost had no well directed episode its entire run.
Let's be real here, the direction of that series was indeed consistent. Consistently mediocre, that is.
Even animation wise, there was almost no strong episode until the Chimera ant arc, and even that wasn't great throughout.
It's just the animation direction provided some relative ease, that even with the least animated episodes, the characters at least looked on model. But that's it!