Oda's age and health problems caught up with him.
As big and ambitious as OP is, Oda shot himself in the foot by prolonging it to 20+ years and never letting his assistants help him with drawing anything more than backgrounds, never outsourcing his coloring (which does take time), never stop from taking on more OP projects than his health can handle.
The art and paneling is only going to get worse from here on out. Fights will be shorter and lazier but peanut gallery reactions will be more plentiful cuz apparently that's what matters more than SH portrayal.