kingdon isn't popular just because Mel is a popular character, Langdon is conventionally attractive, the two of them get a lot of scenes together, and the actors have chemistry
their relationship is thematically relevant to the show
the pitt is about burnout in the high stress environment of an ER post-COVID and making connections, both to do the work well and to survive it
between doctors and nurses and between them and the patients and the patients to the social worker as needed
and there are connections between other pairs of people, super young Javadi is paired with mature student McKay for a while which does open Javadi's eyes to life she's been sheltered from, Javadi gets a crush on Mateo who invites her to the park at the end of the day, Dana is the first to figure out Collins' pregnancy on her own and also speaks with Javadi on her new crush, Robby and Collins come together for a deep conversation after her miscarriage and before he sends her home, Mohan helps the sickle cell patient and the mercury poisoned influencer, Santos overtly tries to make connections to the two med students and is ultimately successful with Whitaker but she also gets protective over the daughter whose mother poisoned her father with progesterone and gets another patient to open up about their suicide attempt while Javadi over identifies with the baseball kid, lots of little new connections or longer formed ones
and then there's Mel on the verge of caretaker burnout as the only one supporting her sister
and Langdon who is basically on a different planet from his wife and gets outright rejected by Robby when he asks if they're friends
both so desperate for connection, someone on their level
and they click, they're the only ones that show up excited to be there (Mel more so than Langdon but he's not nearly as dismayed as Collins by the board when they first come in), Langdon offers Mel opportunities like the crike and Terrence, and compliments her successes and checks in with her and tells her to take breaks as needed while Mel seeks him out for his opinion and keeps up with him
they are the connection in the show, they just met and they make each other better at the job, if only all the doctors and nurses could get along this well, right?
except Langdon is an addict, through Robby the show implies the job broke something in him before the cameras even showed up and what Robby sees as a betrayal from Langdon contributes in turn to Robby's collapse on his worst day, and the parallels and what ifs come out
what if Robby had been as attentive to Langdon as Langdon was to Mel? What if Robby had allowed the connection instead of rejecting Langdon? What if Mel had shown up earlier? Would she have just burned herself out faster?
Langdon and Mel are the high point so Robby and Langdon yelling at each other and trying to tear each other down and talking more at each other than to each other can be the low point
Langdon and Mel improving their relationship in future seasons, moving beyond a day one spark to having more time and experience to deepen their relationship and making each other better doctors in the process is proving the themes of the show, that you need support and connection to do the job well and survive it
so of course people want to extend that into their personal lives so Mel is not alone with her sister and Langdon isn't in a crumbling marriage so they can have connection and support and be better people in their personal lives and not just professionally
Langdon and Mel are also shown as foils to Robby and Collins who once dated and Mel's single with a sister pushing her to make a romantic connection when the connection she's made is with Langdon and Langdon seems well on the way to divorce even before the addiction reveal
and the actors have a lot of chemistry
