Beasts pirate is well-known for their physical strength and durability. Why all their fights so far are too shorts, typically lasts about 2 chapters.
Simple answer is: Oda dont care.
He creates hype. Then he takes you on a journey to that hype's conclusion, but this journey is a train ride, where you get to see a lot of other attractions. Those attractions turn out to be too big, that the actual hype/goal is neglected.
This is what Oda defenders say when confronted: enjoy the ride.