It's crazy isn't it?. The funniest thing is that One Piece brings much more profit to Toei than Maid Dragon brings to KA, but this trash studio can't have the decency to pause the broadcast .
No, it's not just always about the money/profit. It's about the team staff. That's the important thing. And One Piece is Toei's most successful long series, they can't just make it seasonal half way. Then there's the possibility that people lose the interest due to impatience, just like you can see with MHA.
The production of a long series like One Piece is much harder and difficult than a seasonal anime due to the preparations. They often have to rely on outsourced studios. As I said, team staff is important but if everyone is already overworking af due to drawing those ~1400 frames (Idk) by making lots of scenes, there's mostly no room for some moments or even episodes to be produced on. Thus, outsourced studios take this task and - you know - it's obviously not that qualitative. You know, I'd have agreed with you if this was DR or WCI but Wano has been fire so far. It's really enjoying, even more than the manga.
You often see consistent movie quality animations. How could they make it even better than that?