It was a meaningless filler episode
If you mean "filler" in the sense that it was a disposable episodic adventure, wouldn't at least seventy-five percent of the series falls into that category?
Sorry for the confusion, the key adjective was "meaningless", not "filler". I'm totally cool with filler episodes, and actually its probably more like 95% of the series is filler. Very few episodes when you think about it actually advanced the plot. Some of my favorite episodes are filler.
However, as I said: key word was meaningless. This was an episode about a planet that wrestles. They introduce a wrestler. Our hero is forced to wrestle. Then the episode is over. At least TOS "Arena" had a point: Kirk and the Gorn were fighting as proxy for the lives of their crew. Here, it was meaningless entertainment, just like WWE.