Why do you think Lena and Kara are the perfect match?
Lena and Kara are the perfect match. they both come from families that expect SO much from them. They're both trying to be more than their family name. Lena comes from a broken home. Her birth mom died, she's adopted into the Luthor family only to later find out Lionel was her birth father. Her brother who was someone she trusted growing up turned into a psychopathic xenophobe homicidal maniac. Lillian was a narcissistic emotionally abusive woman up until the later seasons. She has trauma galore. Then you have Kara, who came from an oddball messed up family, if we're being honest.. I mean, her aunt and mother fought about Kryptons well-being, her parents sent her off into a pod during the collapse of her world to babysit Kal, only for her pod to be knocked off course, trapping her frozen for years on end. Then when she comes to earth Kal is grown up and doesn't take her in himself, so she doesn't really have anyone to teach her about her powers while growing up with the Danvers (SHE'S ALSO ADOPTED).
Besides those factors, watch them interact. I mean, the first meeting. Immediate heart eyes from both of them, the longing stare. Then they become friends and Lena has such a safe feeling with Kara right off the bat she allows her access to her and her office anytime. The FLOWERS filling Kara's office, simply because Kara wrote a nice piece on her. BUYING CATCO "Well un-quit, I literally can't do this without you". YOUR HONOR LOVE. NOT TO MENTION when Lena was on that plane and it snapped, she risked the whole city telling Lena to climb when she was already struggling holding both sides of the plane.
The bond they have throughout the show. I mean, Kara is Lena's biggest cheerleader. Lena can do no wrong in her eyes. She defended her every single time. And yeah, okay. During their "breakup" she told Lena "If you continue to work with Lex, if you continue with whatever it is you two are planning, I will do everything in my power to stop you. Like I would any other villain." She said that after trying to change the timeline, and in every version of her and Lena, something happened to one or both of them. There was never a good time for her to come out to Lena. But when she called Lena a villain, she felt defeated, she felt lost, she was fighting a losing game at the time. BUT. You know Kara never stopped believing in her. And eventually Lena came around. I mean, they were both devastated during that time and equally lost. Staring at the same photo and have their own separate denial and heartbreak.
When Alex and Kara's dad dies. Lena breaks her no contact faze to tell Kara she was sorry, to give her condolences AND GIVE HER A GRIEF BOOK. Lena's heart was still in it, she never stopped wanting to be there for Kara.
AND WHEN THEY CAME BACK TOGETHER. FIREWORKS. It's like their whole relationship rebooted and sparks flew. The undeniable chemistry from the previous seasons just tripled, the unwavering belief in the other skyrocketed. "Do you really not believe in magic?" I Believe in YOU", Not if it means losing who WE are in the process, then we're no better than she is" "I know you are still processing the fact that you can use magic. I know that I have been pushing you out of your comfort zone, but that's only because I believe in YOU". PLEASE DO YOU SEE THIS.
They've both come from the fucking trenches, fought tooth and nail to get to where they are. Together and separately. But together, they're an unstoppable force. The way they look at each other with the utmost understanding and vulnerability. Lena never doubts Kara, never puts her down. Kara lifts Lena when she is going down a self deprecating road and holds her when she's breaking.
It's written in the god damn stars. The ending of the era, when Lena talks Kara down from her panic about the thought of coming out as Supergirl. "You can't always be our Savior Kara. You shine your light and inspire others to shine theirs. YOUR words, not mine. If somebody does come, if they try to mess with THIS family, then WE will take them on TOGETHER. El Mayarah." ARE YOU KIDDING ME.
They've been a match since day one. Whether you believe it as a solid friendship or more. They were made for each other, to grow together, to love together, to become more than their families.