Why Arrow Just Got Cancelled
5. The Show Peaked In Season 2
When looking at the show's decline in ratings, and why The CW feel they don't need it anymore, there's one fairly simple reason: it peaked back in Season 2.
This was the year of Oliver vs Slade and Arrow vs Deathstroke, and it produced the show's most consistent and electrifying storytelling. It was epic in the threat to Starling City, but also extremely personal between hero and villain. The action went to a new level, the characters were much better developed, the performances stronger, the writing sharper.
It's one of the high-points of the Arrowverse as a whole (matched by Season 1 of The Flash) and even led to a boost in ratings: Season 3 performed better on the back of how good Season 2 was. But then, Season 3 was a letdown, and you can see the drop-off in Season 4. Season 4 was arguably even worse, quality-wise, and you can see the dip in ratings become starker. The show arrested the halt with a back-to-basics fifth season that improved the quality, but once that kind of rot has set in - and a show has gained a reputation for no longer being as good as it used to be - it's difficult to reverse that kind of cultural consensus.