Why Supergirl Just Got Cancelled

5. The Ratings Have Been Declining For Years

One thing that could have played into The CW's decision to end Supergirl now is the fact that its ratings have been in decline for years now.

Now, when you've been on the air for a long time, a decline in the ratings is inevitable and that's certainly not helped by the fact that less people are watching network TV at any one time than they used to - something we've seen reflected in the ratings of all long-running shows in recent years - but Supergirl's have taken some tumbles recently.

The first season debuted with an astounding 13 million viewers on CBS but over the course of the first season that averaged out to around 7 million. It also started strong when it moved to The CW, bringing in a solid 3 million viewers for the smaller network - even outperforming network headliner The Flash on occasion.

However, a sharp decline soon began as it found itself falling below 2 million viewers and, midway through Season 4, it fell below 1 million.

While The CW hasn't been as worried about high ratings on the night as other networks are - particularly in regards to the Arrowverse shows given their popularity worldwide - the fact that only two episodes of Season 5 were able to bring in 1 million viewers and the fact that it hit multiple series lows throughout, it's understandable that all involved decided to end it sooner rather than later.