When The CW announced that Supergirl would end with its sixth season, it also announced that it would do so with a bumper-length final season of 20 episodes - the same amount of episodes as its first. That final season was a bit of a bumpy ride, producing episodes without its title character, not fully focusing on her when she was there, and limiting its central villain with a number of episodic tasks that got a bit repetitive. Nevertheless, it was an improvement over season 5 and it all built towards a potentially heartfelt finale.
Heartfelt is exactly what the series finale was, focusing on the hope that Supergirl inspired around the world during her final battle with Nyxly and Lex Luthor as she overcame her fear of the Phantoms from the Phantom Zone. That's what the Girl of Steel had been known for throughout the show's run, so it only made sense that it focused on it in the finale, while also taking a moment to look back at her growth along the way.
The final battle was a little rushed, but it did see the return of some fan-favorite original characters, including Winn Schott, James Olsen, and Mon-El. But let's be honest, Supergirl was at its best when it focused on the emotion of its stories, and the series finale was full of that, showcasing Alex and Kelly's love through their beautiful wedding sequence. Sure, it would have been nice to see a bit more focus on Kara, but her arc in the finale was more subtle as she contemplated her place as Earth's champion and whether or not she wanted to keep her identity a secret any longer.
With some beautiful character moments, a focus on friendship, a musical performance from Melissa Benoist and Jeremy Jordan, and the long-awaited return of Calista Flockhart as Cat Grant, Supergirl produced a strong finale that bid farewell to its beloved characters, allowing the show to regain some of that heart that it had lost in its final two seasons.