People have come to the realization that one piece has been just a money grabber for a long time now....it was good at the beginning with a good promise because it was new and it needed to be interesting for its survival. That's no more needed for years now. Kinda like Pokemon maybe...maybe not..but basically it has survived and has created a brand for itself(has a bigger market outside the manga I feel with parks, merchandise, theme restaurants, and stuff, shows, and also commercial movies). So now they only need to think about how to milk more. That's why we would get more cliche stuff that can be used in other forms for money grabbers...whether it is fighting/characters/costumes etc. How the series goes and ends...is not something they care much
I bet if it was a series that was not popular or made much money(basically the team struggling to make it not get canceled) the content would be far better.